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DEPARTMENT OF TERRESTRIAL MAGNETISM 

J. A. Fleming, Director 



Scientific Results of Cruise VII of the CARNEGIE during 1928-1929 
under Command of Captain J. P. Ault 



OCEANOGRAPHY — I-A 



Observations and Results in 
Physical Oceanography 



H. U. SVERDRUP F. M. SOULE 
J. A. FLEMING C. C. ENNIS 



CARNEGIE INSTITUTION OF WASHINGTON PUBLICATION 545 

WASHINGTON, D. C. 
1944 



This book first issued September 30, 1944 



PREFACE 



Of the 110,000 nautical milesplanned for the seventh 
cruise of the nonmagnetic ship Carnegie of the Carnegie 
Institution of Washington, nearly one -half had been com- 
pleted on her arrival at Apia, November 28, 1929. The 
extensive program of observation in terrestrial magnet- 
ism, terrestrial electricity, chemical oceanography, 
physical oceanography, marine biology, and marine me- 
teorology was being carried out in virtually every detail. 
Practical techniques and instrumental appliances for 
oceanographic work on a sailing vessel had been most 
successfully developed by Captain J. P. Ault, master and 
chief of the scientific personnel, and his colleagues. The 
high standards established under the energetic and re- 
sourceful leadership of Dr. Louis A. Bauer and his co- 
workers were maintained, and the achievements which 
had marked the previous work of the Carnegie extended. 

But this cruise was tragically the last of the seven 
great adventures represented by the world cruises of the 
vessel. Early in the afternoon of November 29, 1929, 
while she was in the harbor at Apia completing the storage 
of 2000 gallons of gasoline, there was an explosion as a 
result of which Captain Ault and cabin boy Anthony Kolar 
lost their lives, five officers and seamen were injured, 
and the vessel with all her equipment was destroyed. 

In 376 days at sea nearly 45,000 nautical miles had 
been covered (see map, p. iv). In addition to the exten- 
sive magnetic and atmospheric-electric observations, a 
great number of data and marine collections had been 
obtained in the field of chemistry, physics, and biology, 
including bottom samples and depth determinations. 
These observations were made at 182 stations, at an av- 
erage distance apart of 300 nautical miles. The distri- 
bution of these stations is shown in the map, which de- 
lineates also the course followed by the vessel from 
Washington, May 1, 1928, to Apia, November 28, 1929. 
At each station, salinities and temperatures were ob- 
tained at depths of 0, 5, 25, 50, 75, 100, 200, 300, 400, 
500, 700, 1000, 1500, etc., meters, down to the bottom or 
to a maximum of 6000 meters, and complete physical and 
chemical determinations were made. Biological sam- 
ples to the number of 1014 were obtained both by net and 
by pump, usually at 0, 50, and 100 meters. Numerous 
physical and chemical data were obtained at the surface. 
Sonic depths were determined at 1500 points and bottom 
samples were obtained at 87 points. Since, in accord- 
ance with the established policy of the Department of 
Terrestrial Magnetism, all observational data and ma- 
terials were forwarded regularly to Washington from 
each port of call, the records of only one observation 
were lost with the ship, namely, a depth determination 
on the short leg between Pago Pago and Apia. 

The compilations of, and reports on, the scientific 
results obtained during this last cruise of the Carnegie 
are being published under the classifications Physical 
Oceanography, Chemical Oceanography, Meteorology, 
and Biology, in a series numbered, under each subject, 
I, II, and in, etc. 

A general account of the expedition has been prepared 
and published by J. Harland Paul, ship's surgeon and ob- 
server, under the title The last cruise of the Carnegie , 
and contains a brief chapter on the previous cruises of 
the Carnegie , a description of the vessel and her equip- 
ment, and a full narrative of the cruise (Baltimore, Wil- 
liams and Wilkins Company, 1932; xiii + 331 pages with 
198 illustrations). 



The preparations for, and the realization of, the pro- 
gram would have been impossible without the generous 
cooperation, expert advice, and contributions of special 
equipment and books received on all sides from inter- 
ested organizations and investigators both in America 
and in Europe, .among these, the Carnegie Institution of 
Washington is indebted to the following: the United States 
Navy Department, including particularly its Hydrographic 
Office and Naval Research Laboratory; the Signal Corps 
and the Air Corps of the War Department; the National 
Museum, the Bureau of Fisheries, the Weather Bureau, 
the Coast Guard, and the Coast and Geodetic Survey; the 
Scripps Institution of Oceanography of the University of 
California; the Museum of Comparative Zoology of Har- 
vard University; the School of Geography of Clark Uni- 
versity; the American Radio Relay League; the Geophys- 
ical Institute, Bergen, Norway; the Marine Biological 
Association of the United Kingdom, Plymouth, England; 
the German Atlantic Expedition of the Meteor . Institut 
fur Meereskunde, Berlin, Germany; the British Admiral- 
ty, London, England; the Carlsberg Laboratorium, Bu- 
reau International pour l'Exploration de la Mer, and 
LaboratoireHydrographique, Copenhagen, Denmark; and 
many others. Dr. H. U. Sverdrup, now Director of the 
Scripps Institution of Oceanography of the University of 
California, at La Jolla, California, who was then a Re- 
search Associate of the Carnegie Institution of Washing- 
ton at the Geophysical Institute at Bergen, Norway, was 
consulting oceanographer and physicist. 

In summarizing an enterprise such as the magnetic, 
electric, and oceanographic surveys of the Carnegie and 
of her predecessor the Galilee , which covered a quar- 
ter of a century, and which required cooperative effort 
and unselfish interest on the part of many skilled scien- 
tists, it is impossible to allocate full and appropriate 
credit. Captain W. J. Peters laid the broad foundation of 
the work during the early cruises of both vessels, and 
Captain J. P. Ault, who had had the good fortune to serve 
under him, continued and developed that which Captain 
Peters had so well begun. The original plan of the work 
was envisioned by L. A. Bauer, the first Director of the 
Department of Terrestrial Magnetism, Carnegie Institu- 
tion of Washington; the development of suitable methods 
and apparatus was the result of the painstaking efforts of 
his co-workers at Washington. Truly, as was stated by 
Captain Ault in an address during the commemorative 
exercises held on board the Carnegie in San Francisco, 
August 26, 1929, "The story of individual endeavor and 
enterprise, of invention and accomplishment, cannot be 
told." 

Prior to the Carnegie observations on her last cruise, 
knowledge of the physical oceanography of the Pacific 
Ocean was unreliable, and in some parts entirely lacking. 
The Carnegie investigated many areas in which few, and 
sometimes no, observations had been made. Because of 
this, and because of the accuracy of the data gathered, 
the results presented in this volume are valuable. 

Dr. H. U. Sverdrup, Director of the Scripps Institu- 
tion of Oceanography, and F. M. Soule, of the Depart- 
ment of Terrestrial Magnetism, prepared the papers 
that comprise this volume. A considerable part of the 
work required in the reduction of the oceanographic ob- 
servations was done by C. C. Ennis at the Department of 
Terrestrial Magnetism under the direction of Dr. J. A. 
Fleming, Director of the department. Mr. Ennis made a 






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PREFACE 



great number of the computations and prepared all the 
figures. 

Sonic depth finding equipment loaned by the United 
States Navy Department made a program of sounding 
possible. Although the program changed occasionally 
with changing conditions, soundings were usually made 
every four hours. These soundings reveal changes that 
have to be made in our conceptions of the most probable 
course of the depth contours in the oceanic areas trav- 
ersed. 

Salinities were measured by the bridge and titration 
methods, and then compared. The results of the salinity 
work are given in table 2 and in the vertical distribution 
curves (Oceanography I-B, pp. 183-257, and 56-115). 

Bottom samples were collected at the different sta- 
tions with various samplers. These samples were sent 
to Washington for examination. 

In his introduction Dr. Sverdrup states that oceano- 
graphic data accumulated after 1930 have not been con- 



sidered by him in preparing the present volume, and this 
procedure has imposed certain limitations on the discus- 
sion. On the other hand, the Carnegie data have been freely 
placed at the disposal of every oceanographer who has 
needed them in his work, and have, therefore, been wide- 
ly used and discussed from different points of view. Dr. 
Sverdrup has himself used them most extensively, par- 
ticularly in other analyses of the waters and currents of 
the Pacific Ocean such as those appearing in "The oceans, 
their physics, chemistry, and general biology" by him- 
self, Johnson, and Fleming. These later analyses have 
not materially changed the conclusions. 

The present volume is the seventh in the series 
"Scientific results of cruise VII of the Carnegie under 
command of Captain J. P. Ault.'' It is the first of the 
Oceanographic Reports. 

J. A. Fleming 
Director, Department of Terrestrial Magnetism 



GENERAL CONTENTS 

SUBJECT 

I. Observations in Physical Oceanography 

Water Bottles and Thermometer Frames F. 

Subsurface Temperatures H. 

Thermometric Determination of Depth H. 

Determination of Depths at Which Temperatures Were 

Measured and Water Samples Collected H. U. Sverdrup 

Note on the Practical Correction of Deep-Sea Reversing 
Thermometers and the Determination of the Depth of 
Reversal from Protected and Unprotected Thermometers F. M. Soule 

Note on the Computation of the Density of Sea Water and on 
Corrections for Deep-Sea Reversing Thermometers 



Depth to Bottom at Carnegie Stations 

Sonic Depth Work 

Corrections to Sonic Depths Determined on Board the 
Carnegie on Account of Errors in the Timing 

Sounding Velocity 

Determination of Salinity 

On the Accuracy of the Salinity Values 

Bottom Samples- -Collection and Preservation 
II. Results Within Physical Oceanography 

Results Within Physical Oceanography 

Figures 1-38 

Discussion of Carnegie Soundings 
III. Index 



AUTHOR 

M. Soule 
U. Sverdrup 
U. Sverdrup 



C. C. Ennis 
H. U. Sverdrup 
F. M. Soule 

H. U. Sverdrup, F. M. Soule 
F. M. Soule 
F. M. Soule 
H. U. Sverdrup 
F. M. Soule 

H. U. Sverdrup 

H. U. Sverdrup, J. A. Fleming 

F. M. Soule 



Page 
1 

3 

5 

11 

15 

19 

23 
47 
51 

55 
61 
67 
77 
79 
81 
83 
115 
149 
155 



vn 



OBSERVATIONS AND RESULTS IN PHYSICAL OCEANOGRAPHY 



OBSERVATIONS IN PHYSICAL OCEANOGRAPHY 



Water Bottles and Thermometer Frames 
Subsurface Temperatures 
Thermometric Determination of Depth 
Determination of Depths at Which Temper; 

and Water Samples Collected 
Note on the Practical Correction of Deep-Sea Reversing 

Thermometers and the Determination of the Depth of Reversal 

from Protected and Unprotected Thermometers 
Note on the Computation of the Density of Sea Water and on 

Corrections for Deep-Sea Reversing Thermometers 
Depth to Bottom at Carnegie Stations 
Sonic Depth Work 
Corrections of Sonic Depths Determined on Board the Carnegie 

on Account of Errors in the Timing 
Sounding Velocity 
Determination of Salinity 
On the Accuracy of the Salinity Values 
Bottom Samples- -Collection and Preservation 



CONTENTS 








F. M. Soule 


Page 
3 




H. U. Sverdrup 


5 




H. U. Sverdrup 


11 


es Were Measured 








H. U. Sverdrup 


15 



F. M. Soule 


19 


C. C. Ennis 


23 


H. U. Sverdrup 


47 


F. M. Soule 


51 


H. U. Sverdrup, F.M. Soule 


55 


F. M. Soule 


61 


F. M. Soule 


67 


H. U. Sverdrup 


77 


F. M. Soule 


79 



WATER BOTTLES AND THERMOMETER FRAMES 



The water bottles used on the Carnegie for the rou- 
tine collection of water samples were of the Nansen type 
manufactured by Bergen Nautik. This type of bottle con- 
sists of a hollow brass cylinder equipped with valves, 
one in each end. The valves are operated synchronously 
by means of a connecting rod which is attached to the 
clamp that secures the bottle to the cable. When the 
bottle is sent down, this clamp is at the lower end of the 
bottle, the upper end being held to the cable by a pin. 
When the bottle is in this position the valves are open. 
The cable is paid out until the bottle reaches the level 
from which a sample is desired. Then a concentric cy- 
lindrical brass weight called a messenger is placed on 
the cable and released from the surface. The messen- 
ger slides down the cable to the bottle where it trips a 
trigger, pulls the holding pin and thus releases the upper 
end of the bottle from the cable. The bottle falls over 
and in so doing closes the valves in either end; the 
valves are locked in the closed position by a spring, and 
the desired sample is trapped in the bottle. Figure 1 
shows a Nansen water bottle. Normally a series of sev- 
eral bottles are placed on the cable at intervals along its 
length for a single cast. In such a case a messenger is 
placed on the cable just below each bottle (except the 
lowest) and temporarily held in place by a short chain, 
the last link of which is attached to the bottle by means 
of a spring pin. After the surface messenger releases 
the upper end of the first bottle, it slides on down the 
cable to the lower end of the bottle where it releases the 
attached messenger which, in turn, continues down the 
cable. The process is repeated at each bottle. The bot- 
tle is also equipped with an air valve, a stopcock, and a 
removable frame suitable for holding two deep-sea re- 
versing thermometers. For further description of the 
Nansen type water bottle see Helland-Hansen and Nan- 
sen (1926). 



The Nansen bottles used on the Carnegie were tinned 
and the exterior painted white. Because of the absorp- 
tion of dissolved oxygen by tinned brass (see Knudsen, 
1923) the tabulated oxygen values are possibly somewhat 
too low but are comparable with all but the most recent 
observations in which silver lined collecting bottles have 
been used. 

Large water bottles such as the Allen and Meteor 
types, described respectively by Allen (1927) and WOst 
(1926), were used infrequently at shallow depths for the 
collection of microplankton. 

An instrument which it was thought would be of 
great usefulness is a small light reversing water bottle 
for use on the bottom sampling line to obtain water sam- 
ples and temperatures from the layers immediately 
above the bottom. (See fig. 2). Such bottles originally 
were manufactured by Bergen Nautik for the Carnegie 
but arrived on board just prior to the disaster and so 
were not tried out. They operated on the propeller prin- 
ciple described below in connection with thermometer 
reversing frames. Their capacity was 300 ccm and their 
weight 2.32 kg without thermometers. 

Thermometer reversing frames, such as the one 
shown in figure 3, were used at the end of the bottom 
sampling piano wire attached to the drift line about 20 
meters from the end. Equipped with a protected and with 
an unprotected thermometer, the arrangement was used 
to determine the depth at which bottom samples were 
taken, and at the same time it gave measurements of the 
temperature close to the bottom. The frame containing 
the thermometers was hinged off center and held in posi- 
tion by a threaded pin which was withdrawn by the action 
of a small propeller when the line was being hauled in. 
Experiments near the surface indicated that upward mo- 
tion through the water over a distance of about 25 meters 
served to reverse the thermometers. 



LITERATURE CITED 



Allen, W. E. 1927. An improved closing bottle for sub- 
surface sampling of fluids. Science, 65, pp. 66-67. 

Helland-Hansen, B. and F. Nansen. 1926. The eastern 
North Atlantic. Geofys. Pub., 4, no. 2, p. 6. 



Knudsen, M. 1923. Some new oceanographical instru- 
ments. Conseil Perm. Internat. Expl. Mer., Pub. 
Circ. no. 77, pp. 10-12. 

Wust, G. 1926. Bericht uber die Ozeanographischen 
Untersuchungen. 2. Gesellsch. Erdk., Berlin, no. 1, 
p. 28. 



SUBSURFACE TEMPERATURES 



The surface temperature was recorded continuously 
by means of a sea-water thermograph. The instrument 
and its operation are described in the volume dealing 
with the meteorological data, and tables showing hourly 
values of sea-surface temperatures are given in that 
volume and in table 1 of Oceanography I-B. In the fol- 
lowing, therefore, we are concerned with the subsurface 
temperatures only. 

The subsurface temperatures were determined by 
means of protected reversing thermometers of the well- 
known pattern manufactured by Richter and Wiese.l All 
thermometers had been examined at the Physikalische 
Technische Reichsanstalt (PTR) and will be referred to 
by the PTR numbers. The corrections determined by the 
Reichsanstalt will be designated the "PTR corrections." 
Table 1 gives the range for each thermometer, the char- 
acter of graduation, the date of the PTR certificate, and 
the numbers of the stations at which used. 

From the footnotes in table 1 it is seen that a num- 
ber of the thermometers were lost because of accidental 
breaking of cable during the occupation of several sta- 
tions. The remaining thermometers were all lost when 
the Carnegie was destroyed. No determinations of the 
corrections of the thermometers were undertaken at sea 
and, since all thermometers were lost, a re-examination 
is impossible. A large number of protected thermome- 
ters were used in pairs, however, and from the differ- 
ences between the corrected readings of two such ther- 
mometers it is possible to arrive at several conclusions 
as to the accuracy of the observed temperatures, assum- 
ing the PTR corrections to have remained unchanged. 

Before entering on an examination of these differ- 
ences, the possible errors of the temperature observa- 
tions will be briefly discussed. Some of the thermometers 
were divided to one-twentieth degree and others to one- 
tenth. The errors of these two classes of thermometers, 
which for sake of brevity will be referred to as the one- 
twentieth and the one-tenth thermometers, will be treat- 
ed separately. The following sources of error then have 
to be considered: (1) errors of reading; (2) correction 
errors arising from (a) reduction errors, (b) limit of ac- 
curacy of the test, and (c) change of zero point; and (3) 
errors of breaking-off device. 

(1) Errors of reading . All thermometers were read 
to 0.°01 and reading was always made by means of a spe- 
cial reading lens. The accuracy of the reading, there- 
fore, can safely be assumed to lie within the limits 
+ 0.°01. Bohnecke (1927)statesregardingtheone-twentieth 
thermometers that the errors of reading for such ther- 
mometers when read to 0°001 never exceed 0.°005 and as 
a rule were smaller than 0.°003 according to the experi- 
ence at the Reichsanstalt. 

(2a) Correction errors arising from reduction er - 
rors . A correction, as is well known, must be applied to 
the reversing-thermometer reading, since as a rule it is 
read at a temperature differing from the temperature at 
which the column of mercury broke off. The exact for- 
mula for this correction is 

(I + Vq) (T - tj/6100 (1) 

*For detailed description see Wissensch. Ergebn. d. 
Deut. Atlantischen Exped. auf dem Forschungs- und 
Vermessungsschiff Meteor 1925-27, vol. 4, pt. 1. (1932). 



where T is the temperature at which the thermometer 
was reversed, Vq is the volume of the mercury at zero 
degree,^ is the temperature at which the thermometer 
was read, and 6100 is a constant depending on the quality 
of the glass. The temperature at which the thermometer 
was reversed, however, is unknown and in the first ap- 
proximation this temperature, T, may be replaced by the 
reading of the thermometer T". As a second approxima- 
tion, T' may be replaced by (T" + dT"), where dT' is 
equal to the correction which is computed by means of 
formula (1), using T' instead of T. The final formula for 
the second approximation to the correction will thus be 

[(T'+ vo) (T'-t)/6100] [1 + (T'+ v ) + (T'-t)/6100] (2) 

This formula has been derived by Schumacher (1923) and 
represents an improvement of formula (1) commonly 
used. He shows that in extreme cases it may be neces- 
sary to apply still another approximation in order to re- 
duce the reduction error beyond the values of the errors 
of reading, but in the case of the Carnegie observations 
the errors in the correction, K, as computed by means of 
formula (2) never exceeded 0°002 and therefore may be 
disregarded. A practical method of determining the cor- 
rection has been described by Soule (1933). 

(2b) Correction errors arising from limit of accu - 
racy of the test. The corrections of the thermometers 
which were communicated by the PTR and which must be 
applied in addition to the reduction correction, K, have 
been rounded to 0°01. The corrections may be regarded 
as exact within 0.°005 at the time when the thermometers 
were tested; however, the corrections are likely to 
change with time and, according to the experience of the 
Meteor expedition, this change has the character of a 
parallel displacement of the correction curve supposing 
the breaking-off device always to function properly Wtlst 
(1928). The parallel displacement of the correction 
curve may be attributed to a change of the zero point of 
the thermometer. 

(2c) Correction errors arising from change of zero 
point . A change of the zero point of the thermometer 
takes place as a rule some time after the manufacture of 
the thermometer and in most cases may be ascribed to a 
contraction of the bulb which causes a rise of the zero 
point and thus a decrease in the correction which has to 
be applied at 0°. The contraction of the bulb is hastened 
by artificial aging of the thermometers but the process 
usually continues for a long time afterward at a slower 
and slower rate. During the Meteor expedition Bohnecke 
examined the zero points of the greater number of the 
thermometers of the expedition at intervals of about two 
months. From this examination it appears that the zero 
point as a rule rose during the first two to six months 
after the manufacture and that no appreciable changes 
took place later. In several instances a lowering of the 
zero point occurred before the subsequent rise, this type 
of change being characteristic of instruments of very re- 
cent manufacture. In a few instances the variations were 
irregular evidently because of bad functioning of the 
break-off device. These thermometers were easily rec- 
ognized when used together with a perfect thermometer 
because the differences in the indications would vary ir- 
regularly within considerable limits. Only in two cases 
were great variations of the zero point observed (0.°6 



6 
Table 1. 



OBSERVATIONS AND RESULTS IN PHYSICAL OCEANOGRAPHY 



Fabr. 
no. 



Thermometers used on the Carnegie , cruise VII 



PTR no. 



Date of 
PTR 
cert. 



Grad- 
uation 



Range 



1927 



Used at 
stations 



1604 


127552 


Oct 31 


1/10 


-1-30 


1-162 


1605 a 


127553 


31 


1/10 


-1-30 


1- 31 


1606 a 


127554 


31 


1/10 


-1 -30 


1- 31 


1607 a 


127555 


31 


1/10 


-1-30 


1- 31 


1608 a 


127556 


31 


1/10 


-1 -30 


1- 31 


1609 


127557 


31 


1/10 


-1 -30 


1-162 


1610 


127558 


31 


1/10 


-1-30 


1-162 


1611 


127559 


31 


1/10 


-1 -30 


18-150 


1621 


127075 


Nov 9 


1/10 


9-30 


1-162 


1622 


127076 


9 


1/10 


9-30 


1-162 


1623 


127077 


9 


1/10 


9-30 


1-110 


1624 


127078 


9 


1/10 


9-30 


1-162 


1625 


127079 


9 


1/10 


9-30 


1-110 


1626 


127080 


9 


1/10 


9-30 


2-117 


1627 


127081 


9 


1/10 


9-30 


1-162 


1628 


127082 


9 


1/10 


9-30 


1-162 


1629 


127083 


9 


1/10 


9-30 


1-162 


1630 


127084 


9 


1/10 


9-30 


1-151 


1631 


127085 


9 


1/10 


9-30 


1-162 


1632 


127086 


9 


1/10 


9-30 


1-162 


1633 


127087 


9 


1/10 


9-30 


4-162 


1634 


127088 


9 


1/10 


9-30 


2-162 


1635 


127089 


9 


1/10 


9-30 


2-162 


1641 


127584 


30 


1/20 


3-13 


8-162 


1642 


127585 


30 


1/20 


3-13 


7-162 


1643 b 


127586 


30 


1/20 


3-13 


7-151 


1644 


127587 


30 


1/20 


3-13 


7-156 


1645 


127588 


30 


1/20 


3-13 


7-152 


1646 a 


127589 


30 


1/20 


3-13 


8- 30 


1647 a 


127590 


30 


1/20 


3-13 


8- 30 


1648 


127591 
127592 


30 
30 


1/20 
1/20 


3-13 
3-13 




1649 a 


17- 31 


1650 a 


127593 


30 
1928 


1/20 


3-13 


7- 31 


1658b 


502 


Jan 3 


1/20 


-2- 8 


33-150 


1659^ 


503 


3 


1/20 


-2- 8 


33-162 


1660 b 


504 


3 


1/20 


-2- 8 


30-150 


1661 a 


505 


3 


1/20 


-2- 8 


1-131 


1662 b 


506 


3 


1/20 


-2- 8 


46-150 


1663 a 


507 


3 


1/20 


-2- 8 


1- 31 


1664 a 


508 


3 


1/20 


-2- 8 


1- 31 


1665 c 


509 


3 


1/20 


-2- 8 


11- 49 


1666 a 


510 


3 


1/20 


-2- 8 


1- 31 


1667 a 


511 


3 


1/20 


-2- 8 


3- 31 


1668 a 


512 


3 


1/20 


-2- 8 


11- 30 


1669a 


513 


3 


1/20 


-2- 8 


11- 30 


1670 


514 


3 


1/20 


-2- 8 


3-162 


1671 


515 


3 


1/20 


-2- 8 


51-165 


1672 a 


516 


3 


1/20 


-2- 8 


1- 31 


1930 


3376 


Oct 18 


1/20 


3-13 


81-162 


1931 


3377 


18 


1/20 


3-13 


81-153 


1932 


3378 


18 


1/20 


3-13 


72-162 


1933^ 


3379 


18 


1/20 


3-13 


81-154 


1973 


4246 


Dec 6 


1/10 


9-30 


113-162 


1978 


4251 


6 


1/10 


9-30 


113-162 


1979 


4252 


6 


1/10 


9-30 


113-162 


1985d 


4258 


6 


1/10 


9-30 


154-155 


1879 


4259 


6 


1/20 


3-13 


113-162 


1912 


4260 


6 


1/20 


-2- 8 








1929 








2094 L 


158 


Mar 6 


1/20 


-2- 9 


33-162 


2095 b 


159 


6 


1/20 


-2-9 


115-150 


2096 e 


160 


6 


1/20 


-2- 9 


113-142 


2097 b 


161 


6 


1/20 


-2- 9 


116-150 


2098 b 


162 


6 


1/20 


-2- 9 


116-150 


2099 b 


163 


6 


1/20 


-2- 8 


116-150 


2100 


197 


15 


1/10 


-2-30 


116-162 


2101 


198 


15 


1/10 


-2-30 


116-162 



Table 1. Thermometers used on the Carnegie, 
cruise VII --Continued 



Fabr. 
no. 



PTR no. 



Date of 
PTR 
cert. 



Grad- 
uation 



Range 



Used at 
stations 



1929 



2102^ 
2103 b 
2104 b 
2105 
2106 b 
2108 
2109 
2060 
2243 b 
2244 b 
108 
151 
48040 
48066 
1285 
1336a 
1338 
1339 



199 


Mar 15 


200 


15 


201 


15 


202 


15 


203 


15 


205 


15 


206 


15 


264 


Apr 12 


908 


Aug 3 


909 


3 


37339 




40661 




67955 




67958 




88700 




93687 




93699 




93690 





1/10 


-2- 


-30 


118-162 


1/10 


-2- 


-30 


118-150 


1/10 


-2- 


-30 


118-150 


1/10 


-2- 


-30 


118-162 


1/10 


-2 


-30 


118-150 


1/10 


-2 


-30 


119-162 


1/10 


-2- 


-30 


119-162 


1/20 


-2- 


- 9 


130-132 


1/20 


-2 


- 9 


131-150 


1/10 


-2 • 


-30 


142-150 


1/10 


-5 


-16 


50-109 


1/10 


9.5- 


-30 


32 


1/10 


-2- 


-26 


22- 28 


1/10 


-2 


-26 


37- 87 


1/10 


10- 


-35 


17- 21 


1/10 


-2- 


-29 


17- 31 


1/10 


-2- 


-29 


37- 39 


1/10 


-2- 


-29 


29-112 



a Lost at station 32. b Lost at station 151. 

c Lost at station 49. d Lost at station 156. e Lost 

at station 144. 



and 0.°8), perhaps owing to the opening of a bubble in the 
glass. BShnecke states that the amplitude of the change 
of the zero point amounts on the average in the case of 
the one-twentieth thermometers to 0.°015 and in case of 
the one-tenth thermometers to 0.°02, the corresponding 
maximum values being 0.°035 and 0.°08. In this connec- 
tion it may be mentioned that the corrections at zero 
scale division of the fifteen reversing thermometers 
used on the Maud expedition were determined at the 
Reichsanstalt in 1909, 1910, or 1914. The redetermina- 
tions made in 1922 to 1924 showed these corrections had 
remained unchanged in eight cases, had increased by 
Of 01 in two cases, had decreased by 0.°01 in four cases, 
and by 0.°03 in one case, the mean change being -0.°003 
and the maximum -0°03. These results cannot be com- 
pared with the results of the Meteor expedition because 
the small changes of the Maud thermometers may be 
ascribed to the circumstance that the PTR calibration 
had taken place a considerable time after the completion 
of the thermometers by the manufacturer. In the case of 
the Carnegie thermometers, the possibility exists that 
the changes in the zero point may reach the amounts 
which Bohnecke found for the Meteor thermometers. 
Any considerable change of the zero point of one ther- 
mometer, however, can be detected if this thermometer 
had been used together with others and examinations of 
the differences between thermometers which were used 
in pairs should give valuable information. On the basis 
of experience on the Meteor it must be expected further- 
more that thermometers received in 1929 would show 
slightly lower temperatures that those received in 1928, 
because it must be assumed that the zero point has risen 
more for the older thermometers. It must also be ex- 
pected that the temperatures based on the original PTR 
corrections on the whole will be slightly too high because 
of the rise of the zero point but the mean error due to 
this circumstance will hardly exceed 0.°02. 



SUBSURFACE TEMPERATURES 



(3) Errors of the breaking-off device . The errors 
arising from this source can be examined by repeating 
With the shortest possible interval of time the determi- 
nation of the zero point of the thermometer or by com- 
parisons between a perfect and an imperfect thermome- 
ter. The number of thermometers which do not function 
properly, according to Bohnecke's experience, is very 
small and the errors are seldom greater than + 0°02. 
The possible errors are probably somewhat greater for 
the one-tenth thermometers and the limits are estimated 
to be + 0.°03. It happens, however, that the imperfect 
thermometers behave erratically and give readings 
which must be rejected because they are obviously 
wrong. Even a thermometer which as a rule functions 
reliably may for unknown reasons give erroneous re- 
sults, but such cases ordinarily can be detected, expe- 
cially if two thermometers have been attached to the 
same water bottle. 

The preceding discussion can be summarized as fol- 
lows: 



Source 
of error 



Thermometer 
graduated to 1/20° 



Proba- 
ble 
error 



Maxi- 
mum 
error 



Thermometer 
graduated to 1/10° 



Proba- 
ble 
error 



Maxi- 
mum 
error 



(1) Reading 
(2aj Reduction 
(2b) Limited ac- 
curacy of 
test 
(2c) Change of 
zero point 
(3) Breaking- 
off device 



±0.003 ±0.005 
0.000 ±0.002 



±0.005 ±0.01 
0.000 ±0.002 



±0.003 
-0.015 



±0.005 
+ 0.02 to 
-0.035 



±0.003 
-0.02 



±0.005 
+ 0.02 to 
-0.08 



0.000 ±0.02 



0.000 ±0.03 



The probable error of a single temperature deter- 
mination by means of a one-twentieth thermometer not 
again examined after the PTR test, according to this 
compilation, lies between the limits -0°009 and -0.°021, 
and the possible errors lie between the limits 0°052and 
-0.067. The corresponding limits in the case of a ther- 
mometer which is graduated to 0.°1 are -0.°012 to -0.°026 
and 0.°067 to -0.°127, respectively. These limits are only 
approximate and especially the maximum errors must 
be regarded as roughly estimated and probably too great, 
but they furnish a basis for a discussion of the possible 
differences between the indications of two thermometers 
used simultaneously. 

The differences between the indications of two ther- 
mometers which have been used together can be ascribed 
to the same sources as the errors of one single ther- 
mometer and we can, therefore, discuss these differen- 
ces in the same sequence. 

(1) Differences owing to errors of reading. Taking 
account of the maximum errors as stated in the preced- 
ing paragraph, these differences may reach +0.°01 and 
+ 0.°02 respectively, but are, as a rule, considerably 
smaller than +0°01 and disappear when averaging many 
comparisons. 

(2a) Differences arising from reduction errors . 
These differences are always negligible because the 
possible reduction errors, which are smaller than 
0.°002, have the same sign for both thermometers. 

(2b) Differences owing to errors arising from limit 
of accuracy of the test . These differences are systematic 



for a given pair of thermometers but cannot exceed 
+ 0.°01. 

(2c) Differences owing to change of zero point . The 
differences owing to changes of the zero point may reach 
appreciable values because it is not probable that the 
zero points of two thermometers change in the same 
amount although the changes may have the same sign for 
both thermometers. The difference has a systematic 
character and is not eliminated when forming the mean 
value from many comparisons. If two thermometers are 
compared during a long period, it is to be expected that 
the difference will change in the course of time because 
it is not probable that the changes of the zero points of 
the two thermometers are at the same rate. Further- 
more it must be expected that a new thermometer will 
give slightly lower temperatures than an old thermome- 
ter because the zero point of the older thermometer has 
risen more. The differences owing to change of zero 
point, according to the experiences of Dr. Bohnecke, may 
amount to 0.°055 for the one-twentieth thermometers and 
to 0°10 for the one-tenth thermometers. The sign of the 
difference depends only on whether the indication of the 
thermometer giving the lowest reading is subtracted 
from the others or vice versa. 

(3) Differences arising from errors of the breaking - 
off device. These differences may amount to +0.°04 or 
+ 0.°06 respectively but as a rule they are insignificant 
because most of the thermometers function perfectly. 
The differences are not systematic and therefore do not 
influence the mean value of the difference. 

The Results of this discussion are summarized be- 
low: 



Source of 
difference 



Thermometer 
divided to 1/20° 



Proba- 
ble 



Maxi- 
mum 



Thermometer 
divided to 1/10° 



Proba- 
ble 



Maxi- 
mum 



(1) Reading 
(2a) Reduction 
(2b) Limited ac- 
curacy of 
test 
(2c) Change of 
zero point 
(3) Breaking- 
off device 



±0.005 
0.000 



±0.01 
0.000 



0.003 0.01 
0.015 0.055 
0.000 ±0.04 



0.01 ±0.02 
0.000 0.000 



0.003 0.01 
0.020 0.10 
0.000 ±0.06 



From this compilation it appears that for one compari- 
son the probable difference between two thermometers 
which both are divided to 1/20° is 0.°023 and on the av- 
erage for a number of comparisons it is 0.°013 because 
the errors of reading cancel. In order to find the range 
over which the differences may be distributed we have to 
take into account the maximum differences which may 
result from errors of reading and errors of the breaking- 
off device, considering that the errors due to limited ac- 
curacy of test and from change in zero point are sys- 
tematic. Assuming these differences to be negative we 
find the limits -0.°068 to + 0.°032, and assuming the dif- 
ference to be positive we find the limits -0.°032 to 
+ 0.°068, and in both cases a range of 0.°100. This range 
is reduced to 0.°020 if the breaking-off device functions 
perfectly. The maximum value of the difference at one 
single comparison is 0°115 and the maximum average 
value of many comparisons is 0.°066 with a range of 
0.°100 as before. In case of the thermometers which are 



8 



OBSERVATIONS AND RESULTS IN PHYSICAL OCEANOGRAPHY 



divided to 1/10° we find a probable difference of 0.°033 
at one single comparison and a probable average differ- 
ence of 0.°023, the maximum range of the differences 
being 0.°160 or 0.°040 if the breaking-off device functions 
perfectly. The corresponding maximum values are 
0.°190 and 0.°110 with a range of 0°160. From this dis- 
cussion it appears that a study of the differences be- 
tween the corrected readings of thermometers, which 
have been used in pairs, will help to clarify the question 
about the probable and possible errors of the single 
temperature observations. 

Table 2 contains the results of the comparisons be- 
tween thermometers which were divided to 1/20°. Here 
the reduced reading of the thermometer with the highest 
PTR number has been subtracted from the reduced 

Table 2. Comparisons between thermometers which 
were divided to one-twentieth of a degree 



PTR nos. 



No. of 
compar- 
isons 



Mean 
differ- 
ence 



Range 



Used at 
stations 



127584 

127585- 

127585 

127585 

127586 

127586 

127586- 

127586- 

127587- 

127589- 

127592- 

127593- 

502- 

502- 

505- 

507- 

512- 

3376- 

3376- 

3378- 

158- 

161- 



127585 

127586 

3378 

161 

503 

514 

3376 

909 

127588 

127590 

127593 

514 

503 

504 

508 

510 

513 

3379 

3378 

3379 

159 

908 



4 

35 

38 

16 

29 

10 

3 

5 

5 

7 

10 

7 

21 

38 

19 

20 

7 

4 

2 

2 

15 

10 



-0.024 

0.006 

0.005 

-0.004 

-0.025 

-0.017 

0.006 

-0.015 

0.004 

-0.005 

-0.017 

-0.004 

-0.003 

0.004 

-0.002 

0.012 

0.008 

0.006 

0.003 

-0.014 

-0.003 

0.050 



0.014 
0.045 
0.031 
0.026 
0.016 
0.041 
0.021 
0.010 
0.010 
0.022 
0.019 
0.030 
0.017 
0.049 
0.024 
0.039 
0.038 
0.030 
0.012 
0.009 
0.025 
0.016 



152-157 

7- 60 

72-114 

116-134 
78-114 
61- 77 

121-126 

142-149 

7- 13 

8- 30 
17- 

7- 

32- 

53- 91 

3- 31 

3- 31 

11- 30 

81- 91 

116-118 

152-153 

115-132 

140-150 



31 

14 
52 



reading of the thermometer with the lowest PTR number. 
The signs of the differences are, therefore, accidental 
and on the average for all thermometers the difference 
ought to disappear. The table also gives the number of 
comparisons for the different pairs, the average differ- 
ence, the range of the differences, and the number of 
stations at which the thermometers were used together. 
The last-named information is not complete inasmuch 
as only the first and last stations at which thermometers 
were used have been entered. 

Table 3 contains the corresponding information for 
the cases in which one of the thermometers was divided 
to 1/20° and the other to 1/10°, and table 4 for the 
cases in which both thermometers were divided to 1/10°. 
It should be noted that a total of thirty-six cases has 
been omitted when preparing these tables because the 
differences were so great that one of the thermometers 
obviously was out of order. 

From these tables it is seen that the mean differ- 
ence reaches or exceeds the value of 0.°03 in three cases 
only. The difference (161-908) is 0.°05 and this differ- 
ence must be attributed to an error in the correction of 



thermometer 908 because 161 was used in combination 
with 127585 and 203, and was found in agreement with 
these. In order to bring thermometer 908 in agreement 
with the others we must change the correction of this 
thermometer by +0.°05. This has been done in the final 
revision of the temperatures. The other conspicuous 

Table 3. Comparisons between thermometers which 

were divided to one-twentieth or 

one-tenth of a degree 



PTR nos. 



No. of 
compar- 
isons 



Mean 
differ- 
ence 



Range 



Used at 
stations 



127552- 

127552- 

127557- 

127558- 

127077- 

127585- 

502- 

503- 

3376- 

3378- 

3379- 

3379- 

159- 

161- 

37339- 



127584 

514 

502 

127584 

127587 

37339 

200 

198 

205 

203 

4258 

4259 

201 

203 

514 



50 

10 

26 

1 

6 

9 

15 

11 

11 

6 

1 

6 

17 

3 

2 



0.020 
-0.005 
-0.012 
0.015 
0.005 
0.016 
0.013 
0.015 
0.013 
0.005 
0.015 
0.004 
0.001 
0.003 
-0.042 



0.053 
0.032 
0.036 

0.013 

0.031 
0.056 
0.031 
0.041 
0.021 

0.026 
0.035 
0.017 
0.031 



92-151 
152-162 

92-119 
158 

36- 46 

61- 71 
133-150 
152-162 
153-162 
121-126 

154 
121-126 
133-150 
136-139 

59- 60 



Table 4. Comparisons between thermometers which 
were divided to one-tenth of a degree 



PTR nos. 



No. of 
compar- 



Mean 
differ- 
ence 



Range 



Used at 
stations 



127552- 

127554- 

127555- 

127558- 

127558- 

127559- 

127559- 

127559- 

127075- 

127076- 

127076- 

127077- 

127077- 

127078- 

127078- 

127080- 

127081- 

127083- 

127084- 

127084- 

127085- 

127085- 

127087- 

127087- 

127087- 

127088- 

127089- 

4251- 

199- 

200- 

202- 

202- 

202- 

205- 



127557 

127556 

127558 

127075 

198 

127076 

127087 

67958 

127076 

127077 

127078 

127079 

37339 

127079 

127089 

127086 

127082 

127084 

127088 

127088 

127086 

127086 

127089 

127088 

203 

127089 

206 

4252 

206 

201 

203 

205 

4259 

206 



91 
29 

3 

4 
37 
20 

7 

3 
34 
31 
53 
29 

6 
24 
11 

9 
126 
22 
38 
48 
30 
98 
46 
27 

6 
23 

4 

16 
25 
14 

3 
29 
10 

2 



0.010 
-0.004 

0.007 
-0.002 

0.009 
-0.008 
-0.001 

0.023 
-0.027 

0.011 

0.013 

0.000 

0.030 
-0.008 
-0.015 

0.008 

0.007 
-0.014 

0.017 
-0.008 
-0.024 

0.007 

0.008 
-0.001 

0.005 
-0.001 

0.006 
-0.008 

0.003 

0.000 
-0.028 

0.003 
-0.004 

0.012 



0.050 
0.040 
0.060 
0.010 
0.070 
0.044 
0.032 
0.028 
0.065 
0.066 
0.064 
0.069 
0.024 
0.066 
0.044 
0.030 
0.067 
0.060 
0.058 
0.055 
0.063 
0.061 
0.083 
0.034 
0.040 
0.031 
0.019 
0.045 
0.033 
0.037 
0.051 
0.066 
0.048 
0.005 



1- 91 

1- 31 

1- 2 

3- 6 

116-151 

40- 60 

20- 36 

37- 39 

127-162 

1- 34 

61-115 

74-110 

51- 58 

1- 32 

152-162 

105-117 

1-162 

1- 30 

33- 70 

71-117 

1- 43 
44-162 
44-118 

136-162 
127-135 

2- 32 
148-151 
113-162 
121-147 
118-132 
118-120 
121-151 
152-162 
119-120 



SUBSURFACE TEMPERATURES 



differences are: (37339-514) = -0.°041 and (37339-127077) 
= -0.°30. The first of these differences, -0.°041, cannot 
be given any great weight because it is based on two 
comparisons only. In these combinations thermometer 
37339 is an old thermometer which was examined at 
PTR in 1910 and re-examined in 1918 and 1922 to 1924. 
On these three occasions the same correction at zero 
was found. It should be expected, therefore, that 37339 
gives correct temperatures. The results may be inter- 
preted to mean that the two new thermometers, 514 and 
127077, gave temperatures too high. Thermometer 
37339 was used in combination with a third new ther- 
mometer and the difference had the same sign also in 
this case, namely, (339-127585) = -0°016. Considering 
that we should expect the zero point of the new thermom- 
eter to rise, it is indeed probable that these gave tem- 
peratures which were slightly too high when corrected 
by means of the original PTR values and that the cor- 
rections of the three thermometers 127077, 514, and 
127585 actually should be lowered by about 0f02or0f03. 
Another old thermometer, 87958, was used in combina- 
tion with one of the new thermometers and the difference 
was of the same sign as above, being (67958-127559) = 
-0.°023. The correction of thermometer 127559 should 
thus, perhaps, be lowered by 0°02. We have no possibil- 
ity of estimating the possible changes in all the other 
thermometers, however, and it therefore seems inad- 
visable to introduce any changes in these isolated cases, 
especially since the mean differences always are based 
on less than ten comparisons and therefore are uncer- 
tain. Instead of changing the original PTR correction we 
shall estimate, on the basis of the differences in tables 
2, 3, and 4, the possible errors which are introduced by 
retaining the PTR corrections. 

When discussing the probable differences between 
two one-twentieth thermometers, it was found that this 
difference, as a rule, is not greater than 0°013. From 
table 2 it is seen that, omitting 908, the difference is 
smaller than 0.°013 in fifteen of twenty-one cases and 
that 'the greatest observed difference is 0.°025. The dif- 
ferences in the change of zero point, thus, have not ex- 
ceeded 0.°025. The absolute change for each thermome- 
ter is unknown, but on the average this change has prob- 
ably amounted to -0.°015. Considering that it is not 
probable that two thermometers have been combined 
which have both changed appreciably, we can safely state 
that the systematic error of the single thermometers, as 
a rule, is smaller than 0.°02 and never greater than0.°03. 

The ranges over which the differences are distribu- 
ted give an idea of the errors of reading and of the 
breaking-off device and thus an idea of the error of one 
single temperature determination. The maximum range 
was estimated to Of 100 and in case the breaking-off de- 
vice always functioned perfectly we should expect the 
range to remain smaller than 0°020. We find that the 
range is smaller than 0.°020 in eight of twenty-one cases, 
the maximum range being 0.°049. We therefore may 
conclude that the errors of reading and of the breaking- 
off device never exceeded Of 03 and, since tha range is 
smaller than Of 031 in sixteen of twenty -two cases, that 
the errors as a rule were smaller than 0.°015. The er- 
ror of one single temperature determination by means 
of these theremometers, therefore, is smaller generally 
than 0.°035, ranging from -Of 005 to -0.°035, and the error 
is in no case greater than + 0f06. 

Turning next to the thermometers which are divided 
to 1/10° we find no greater scattering of the mean 



differences than in case of the one-twentieth thermometers 
The probable mean difference between the one-tenth 
thermometers was estimated to 0.°023 and the maximum 
difference to 0.°160. We find a difference which is small- 
er than 0.023 in twenty-nine of thirty-four cases, and a 
maximum difference of 0.°030. Since the expected aver- 
age change of the zero point for these thermometers is 
-0.°02, we may safely state that the systematic error of 
one single thermometer, as a rule, is smaller than 
Of 025 and never exceeds Of 035. The ranges of the dif- 
ferences are, as a rule, greater for these thermometers 
than for the one-twentieth thermometers as should be 
expected because both the errors of reading and of the 
breaking-off device inevitably are greater. The maxi- 
mum range was estimated to 0.°160 and in case the 
breaking-off device functioned perfectly, to Of 040. We 
find that the range is smaller than 0.°040 in twelve of 
thirty-three cases and never greater than 0.°083. The 
errors due to reading and breaking-off may, therefore, 
reach Of 05 but, as a rule, are considerably smaller than 
0.°02. Thus the total error of one single temperature 
determination is, as a rule, smaller than 0.°045 and nev- 
er greater than 0:°085. 

These conclusions are supported by an examination 
of the cases in which a one-twentieth thermometer was 
used simultaneously with a one-tenth thermometer. The 
mean differences are of the same order as before and 
do not exceed 0.°020, omitting thermometer 37339. The 
ranges usually are greater than for the one-twentieth 
thermometers but smaller than for the one-tenth ther- 
mometers. If we subtract the corrected readings of the 
one-twentieth thermometers from the corrected read- 
ings of the one-tenth thermometers, we find a positive 
difference in three and a negative difference in ten 
cases, omitting thermometer 37339. The unweighted 
mean difference is -0.°0035. From this result it appears 
that the corrections of the one-tenth thermometers have 
not changed more than the corrections of the one-twentieth 
thermometers. Since the corrected readings of the lat- 
ter are slightly higher, the zero point of these thermom- 
eters seems to have risen more than the zero point of 
the one-tenth thermometers. It should thus be safe to 
assume that the zero point of the one-tenth thermome- 
ters has, as a rule, not risen more than Of 025 and never' 
more than 0.°035. 

When discussing the possible differences, attention 
was drawn to the circumstance that the differences be- 
tween the two thermometers which were compared dur- 
ing a long period should be expected to change, because 
the changes of the zero points of the two thermometers 
could not be assumed to follow each other. From table 
4 it is seen that the differences between thermometers 
127084 and 127088 and thermometers 127085 and 127086 
have changed considerably, but the changes are in all 
other cases small. A noteworthy change in the differ- 
ence, therefore, seldom occurs. It was also mentioned 
that older thermometers probably would give slightly 
higher temperatures than more recently made thermom- 
eters because the zero point of the former had risen 
more. The cases in which a new thermometer was used 
together with an older one are compiled in table 5. A 
"new thermometer" is defined as one tested at PTR 
less than eight months before its use and an "old ther- 
mometer" is defined as one tested at least twelve 
months earlier than a new one. The values given are 
differences obtained by subtracting the reading of the 
new thermometer from that of the old one. It is seen 



10 



OBSERVATIONS AND RESULTS IN PHYSICAL OCEANOGRAPHY 



Table 5. Comparisons between thermometers which 

were used during July, September, October, and 

November, 1929, and had been calibrated either 

during October, November, 1927, or January, 

1928 (old thermometers) or during March 

or August, 1929 (new thermometers) 



Old minus new 


No. of 


Mean 


thermometer 


compar- 


differ- 


PTR no. 


isons 


ence 


127558-198 


37 


o 

0.009 


127087-203 


6 


0.005 


127089-206 


4 


0.006 


127585-161 


16 


-0.004 


127586-909 


5 


-0.015 


502-200 


15 


0.013 


503-198 


11 


0.015 




0.070 
0.040 
0.019 
0.026 
0.010 
0.056 
0.031 



Weighted mean 



0.009 



that the differences are positive in five of the seven 
cases, the mean weighted difference being 0.009. The 
old thermometers thus give slightly higher temperatures 
than the new ones, as should be expected. The conclusions 
which were drawn from the results of Dr. Bflhnecke's 
examination of similar thermometers are thus confirmed. 

The final conclusion of this discussion is that most 
of the thermometers give temperatures which are sys- 
tematically too high, but that the errors are as a rule 
smaller than 0.°02 and in no case greater than 0.°035. A 
single temperature observation may be affected also by 
accidental errors, which, as a rule are considerably 
smaller than 0f02 and in the case of the one-twentieth 
thermometers never greater than Of 03 nor more than 
0f04 in the case of the one-tenth thermometers. These 
accidental errors could not have been avoided but the 
systematic errors could have been reduced had it been 
possible to re-examine the thermometers after their 
use. The systematic errors, however, are so small that 
in most cases they are of no significance. 

This conclusion is verified by an examination of the 
temperatures at great depth at stations in the Peruvian 
basin. Stations 68 to 79 are all located in this basin in 



Table 6. Temperature observations below a level of 
2700 meters in the Peruvian basin 



Station 


Depth in 


Thermometer 


Temperature 


no. 


meters 


no. 


centigrade 


69 


2781 


127502 


1.83 




2781 


127504 


1.83 




3188 


127506 


1.81 


70 


2907 


127558 


1.82 




3333 


127502 


1.83 




3333 


127504 


1.83 




3760 


127506 


1.84 


71 


2963 


127506 


1.81 


72 


2781 


127558 


1.82 




3189 


127502 


1.82 




3189 


127504 


1.82 




3603 


127506 


1.84 


74 


2897 


127558 


1.84 




3313 


127502 


1.83 




3313 


127504 


1.82 




3735 


127506 


1.81 


76 


3181 


127502 


1.84 




3181 


127504 


1.83 


77 


2721 


127506 


1.84 


78 


2803 


127502 


1.82 




2803 


127504 


1.82 




3138 


127506 


1.82 



which the water at great depths appears to be very uni- 
form, since it is not in direct communication with water 
in adjacent areas. The observations from this region 
show that this is true because the same temperature is 
found at all stations below a depth of 2700 meters. The 
agreement between the individual observations is good 
as evident from the compilation in table 6. 

From the data in table 6 we find the following mean 
values: 

Thermometer nos. 127558 127502 127504 127506 

Mean temperature, °C 1.827 1.828 1.825 1.824 

and none of the individual values deviate as much as 
0.°02 from these mean values. There is, thus, an excel- 
lent agreement between the four thermometers in ques- 
tion and the error of the individual observations appears 
to be well within the limits which were stated above. 



LITERATURE CITED 



Bohnecke, G. 1927. Veroff. Inst. Meeresk., A, no. 17, 

p. 6. 
Schumacher, A. 1923. Ann. Hydrog., vol. 51, pp. 273- 

280. 



Soule, F. M. 1933. Hydrog. Rev., vol. 10, pp. 126-130, 

May. 
Wiist, G. 1928. Ztschr. Gesellsch. Erdk., Erganzung- 

sheft 3, pp. 66-83. 



THERMOMETRIC DETERMINATION OF DEPTH 



The thermometric method for determining depths in 
the sea has recently been discussed by Dr. A. Schumacher 
(1923) and part of this discussion will be repeated here 
for the sake of completeness. .An unprotected thermom- 
eter which is subjected to a certain pressure will show 
a fictitious temperature which can be regarded as con- 
sisting of the actual temperature of the surroundings 
plus the effect of the compressibility of the glass. On 
account of this pressure effect the reading of the ther- 
mometer will be higher than the reading corresponding 
to the temperature of the surroundings and the increase 
of the reading per unit increase of pressure can be de- 
termined in laboratory. The difference between the in- 
dications of two thermometers, one protected against 
pressure and one unprotected, which both are subjected 
to the same pressure in the same surroundings, can on 
the other hand be used for determining the pressure, as- 
suming the pressure coefficient of the unprotected ther- 
mometer to be known. This method is used in oceano- 
graphic work. Two thermometers, one protected and 
one unprotected, are attached to the same water bottle 
and the pressure at which the thermometers were re- 
versed can be computed from the corrected readings. 
Knowing the average density of the water from the sur- 
face and down to the level where the thermometers were 
reversed, the depth can be found. Since the pressure co- 
efficient of the thermometers is given in degree centi- 
grade per kg/cm2 of increase in pressure and since the 
pressure of 10 meters of water of density 1 is equal to 
1 kg/cm2, we get: p 10 M (1 ) 

q-/°m 

where D means the depth in meters, A the difference 
between the corrected readings of the two thermometers, 
q the pressure coefficient of the unprotected thermome- 
ter, andp m the mean density from the surface to the 
level at which the thermometers were reversed. 

The corrections which must be applied to the read- 
ing of the protected reversing thermometer have already 
been discussed. The correction to be applied to the 
reading of the unprotected thermometer because it was 
read off at a temperature which differs from the tem- 
perature at which it was reversed, is found by means of 
the same formula: 

K . (T. ♦ v ) (Tp - t) 

6100 

where T u means the "temperature" of the unprotected 
thermometer v Q the volume of mercury at zero degrees 
expressed in degrees, Tp the temperature at which the 
thermometer was reversed, t the temperature at which 
it was read off and where 6100 is a constant which de- 
pends on the quality of the glass. The temperature at 
which the thermometer was reversed is known exactly 
from the indication of the protected thermometer, but 
the indication of the unprotected thermometer at rever- 
sal is not known. As a first approximation the reading 
of the unprotected thermometer, T u ' is introduced in 
equation (2) instead of T u . This introduction leads in the 
case of the Carnegie observations to errors which never 
exceed Of 005 and may be regarded as negligible. The 
correction on account of the thermometer being read at 
a temperature which differs from the temperature at 



reversal has, therefore, been computed by means of the 
formula: 

(T u ' + v ) (Tp - t) 



K = 



(3) 



6100 



To the correction K the scale correction at the temper- 
ature of reading has to be added. Practical methods of 
determining this correction and of determining the depth 
have been described by Ennis (1933) and Soule (1933). 

After these remarks about the corrections of the un- 
protected thermometers, we can turn to a discussion of 
the accuracy of the depth as determined by means of 
pressure thermometers (equation 1). Following the pro- 
cedure of Schumacher, we compute the inaccuracy in the 
depth which would result from inaccuracy in the quanti- 
ties At, q, and m : 



l)dD 



10 



q Pro. 



-dAt error inD arising from an error dAt in At 



2) dD = IQAt dq error in D arising from an error dq in q 

q 2 Pm 

3) dD=- 9 d m error in D arising from an error d p m inp 

<lPni 

1. The pressure coefficient for the Carnegie thermome- 
ter values was between 0.07 and 0.09. For the mean 

density we may introduce 1.035. The factor lies, 

therefore, between the limits 138 and 107 and an error 
in the temperature difference of 0.01 introduces, there- 
fore, an error of 1.4 to 1.1 meter. The error of the dif- 
ference depends on the accuracy of the two thermome- 
ters. We have already discussed the accuracy of the 
protected reversing thermometers and have arrived at 
the conclusion that the error of one single temperature 
determination is, as a rule, considerably smaller than 
+ 0.04 and never greater than +0.075. As to the errors 
of the unprotected thermometers, we assume, since 
these have a more narrow division of the scale, that the 
errors may be twice as great--that means generally 
smaller than +0.08 and never greater than +0.15. The 
error in the difference between the corrected readings of 
a protected and an unprotected thermometer will there- 
fore as a rule be considerably smaller than +0.12 and 
never greater than +0.225. The error in depth arising 
from these errors will usually be considerably smaller 
than +16 and never greater than +31 meters. 

2. The pressure factor q, was determined at the Physik- 
kalische-Technische Reichsanstalt, Charlottenberg, and 
entered on the certificate of the thermometer to the 
fourth decimal place. Assuming the last decimal place 
to be correct (which means the error in the factor q to 
be smaller than 0.005), we find, taking /o m as a constant 
and equal to 1.035: 



Maximum 
error in D 


Temperature difference 


10 


20 


30 


40 


q = 0.07 
q = 0.09 


12 3 4 
112 2 



11 



12 



OBSERVATIONS AND RESULTS IN PHYSICAL OCEANOGRAPHY 



The errors in depth introduced by the uncertainty in 
q appear thus to be small but it has to be considered 
that the pressure coefficient is not quite independent of 
the temperature and that it also may change in course of 
time, and the possible errors, therefore, are two or 
three times as great as those which are stated above. 
3. The mean density of the water from the surface and 
to the level where the thermometers were reversed is 
easily determined with an accuracy of 0.0005. Assuming 
the mean value of the density to be constant and equal to 
1.035 we find: 



Maximum 


Temperatur 


e difference 


error in D 


10 


20 


30 


40 


q = 0.07 
q = 0.09 


1 
1 


1 

1 


2 3 
2 2 



The errors which are introduced on account of uncer- 
tainty as to the density are thus always small. 

Summing up the results of this discussion, consider- 
ing that a temperature difference of 10° roughly corre- 
sponds to a depth of 1250 meters, we find that the errors 
in the depth as determined by means of unprotected and 
protected thermometers probably lie within a limit 



Depth in 
meters 



Maximum error 
probably within 



1000 
2000 
3000 
4000 
5000 



±20 
±21 
±24 
±28 
±32 



The errors of the thermometers enter here with the 
greatest weight. 

In his discussion of the " Meteor " data, Wust (1932) 
has shown that errors due to errors of coefficient q in- 
crease more with increasing depth than supposed here, 
but simultaneously he assumes the errors due to errors 
of reading to be smaller. His estimate of the greatest 
possible total error gives, therefore, smaller values at 
small depths, but greater values at great depths. He ob- 
tains, for instance, the values +14 meters and +49 me- 
ters at 1000 and 5000 meters, respectively, whereas 
our estimates are +20 meters and +32 meters. His 
final conclusion is that at depth below 1000 meters the 
mean accuracy of the thermometric determination of 
depth is from 0.6 to 0.4 per cent, whereas our final re- 
sults, after discussion of the actual values, gives mean 
accuracy of about 1 per cent at 1000 meters and 0.5 per 
cent below 3000 meters. 

In order to test this result, the cases have been ex- 
amined in which the wire angle was equal to 5° or small- 
er. In these cases the wire length gives an accurate 
value of the depth and a comparison with the depths ob- 
tained by means of pressure thermometers furnishes 
data for an estimate of the possible errors in the ther- 
mometric determination of the depth. The cases in which 
the wire angle was from 6° to 10° were also studied as 
the depth corresponds closely to the wire length even 
when the angle is 10°. If the wire angle remained equal 
to 10° from the surface and down to the greatest depth, 
a wire length of 1000 meters would correspond to a depth 
of 985 meters, but as a rule the wire is curved and the 
difference between the wire length and the depth is 
smaller. 

Table 1 contains the results of the comparisons be- 
tween the depths as obtained by thermometers and the 



Table 1. Differences between wire lengths and thermometer depths 



Wire angle 0° to 5 ( 



Wire angle 6° to 10° 



PTR 

no. 



No. of 
observa- 
tions 



Mean 
depth, 
meters 



Mean 
differ - 

ence, 
meters 



Total 
range, 
meters 



No. of 
observa- 
tions 



Mean 
depth, 
meters 



Mean 
differ - 

ence, 
meters 



Total 
range, 
meters 



838 


6 


365 


- 0.5 


14 


6a 


372 


- 1.7 


13 


865 


4b 


145 


- 3.0 


10 


3a 


158 


- 6.3 


13 


866 


0b 








4 


608 


6.0 


21 


868 


2 


2215 


4.5 


7 


2 


2898 


23.5 


5 


869 


2 


1241 


- 3.0 


4 


2 U 


1237 


8.5 


19 


990 


, 








lb 


51 


3.0 


... 


1688 


• • • 






• • • 


1 


51 


6.0 


... 


1689 


7 


160 


- 2.3 


5 


7 


87 


- 3.0 


5 


1690 


16 


409 


- 2.4 


21 


12b 


282 


- 1.6 


9 


1691 


11 


193 


- 2.7 


10 


6^ 


274 


- 0.5 


6 


1692 


2 


530 


- 2.0 


6 


3b 


174 


0.3 


13 


1693 


15 


818 


- 5.3 


17 


15 


516 


- 2.5 


24 


1694 










lb 


203 


- 1.0 


... 


1695 


18 


257 


- 2.1 


13 


16 a 


259 


- 0.6 


11 


1696 


8 


2561 


-20.9 


37 


14 


2810 


-13.1 


45 


1698 


1 


3072 


-13.0 


.. 


1 


939 


2.0 


... 


1699 


1 


4075 


1.0 


■ ■ • 


3 


1283 


10.3 


31 


1701 


2 


1645 


9.0 


22 


2 


199 


- 7.0 


4 


1702 


1 


1021 


0.0 


.. 


1 


547 


8.0 


... 


1703 


1 


2042 


0.0 




2 


1070 


10.5 


25 


2993 


2 


3211 


-23.0 


18 


2 


3924 


- 0.5 


. 1 


2994 


2 


1049 


2.0 


12 


12 u 


1123 


10.0 


19 


2995 


3 


1104 


0.0 


16 


9b 


648 


- 0.6 


18 


2996 


5 


1565 


11.6 


17 


12 


2005 


14.9 


35 



a Two cases omitted. 



bone case omitted. 



THERMOMETRIC DETERMINATION OF DEPTH 
Table 2. Number of cases where the difference lies between stated limits 



13 



Wire angle 



Interval of difference: wire length minus thermometer depth in meters 



to 5.0 



5.1 to 10.0 



10.1 to 15.0 



15.1 to 20 



20.1 to 25.0 



to 5 
6 to 10 



14 
12 



wire length for the different pressure thermometers. 
The tabic gives the number of the thermometer, the num- 
ber of observations with this thermometer, the mean 
difference between the wire length and thermometer 
depth, the total range of these differences, and the mean 
depth as obtained by thermometers. These data are en- 
tered for wire angles 0° to 5° and 6° to 10°. 

An inspection of the table shows that the differences 
in depth between the wire lengths and thermometer 
depths as a rule are smaller than 5 meters if the wire 
angle is from 0° to 5° and smaller than 10 meters if 
the wire angle is from 6° to 10° (see table 2). 

Only in three instances the mean difference is so 
great that an error in either the correction of the ther- 
mometers or the pressure factor seems to have influ- 
enced the mean difference. This applies to thermome- 
ters 1696, 2993, and 2996. According to an inspection 
of the single values it seems probable that the correc- 
tions of these thermometers have changed since they 
were determined at PTR and, since an error in the tem- 
perature correction introduces an error which is inde- 
pendent of depth, the simplest procedure is to apply a 
constant correction to the depths which are computed on 
the basis of the original temperature corrections. For 
the depths derived by means of these thermometers the 
following corrections have, therefore, been adopted: 



Depth by thermometer 1696: 
Depth by thermometer 2993: 
Depth by thermometer 2996: 



correction: -20 meters; 
correction: -10 meters; 
correction: +10 meters. 



After application of these corrections we find the follow- 
ing mean differences: 

Wire angle 0° to 5°. Wire length minus ther- 
mometer depth: -1.9 meters (109 cases). 
Wire angle 6° to 10°. Wire length minus ther- 
mometer depth: +3.2 meters (137 cases). 

It is seen that the mean thermometer depth is slight- 
ly greater than the mean wire length in case the wire 
angle is between 0° and 5°. This result may be owing to 
systematic errors in the corrections of the thermome- 



ter (a greater rise of the zero point of the unprotected 
thermometers than of the protected thermometers would 
introduce an error of this sign) or it may be owing to a 
small systematic error of the meter wheel, used for 
measuring the wire length. It is of greater interest to 
state that the difference increases when the wire angle 
increases as should be expected. 

Examining the total ranges of the differences we find 
that these are much smaller than the possible ranges 
which were estimated on the basis of. the sources of er- 
rors. We found that these errors might lead to errors 
in the depth between +20 and -20 meters for depths 
smaller than 1000 meters, which means that the range of 
the differences between the exact values and the meas- 
ured values of the depth might amount to 40 meters. At 
greater depths this range would be greater. When com- 
paring the thermometer depth with wire length we have 
furthermore to bear in mind that the reading of the me- 
ter wheel may not indicate the exact wire length because 
the wire may have slipped on the wheel and we must, 
therefore, expect the ranges in table 1 to be greater than 
the estimated ranges (p. 12) provided that the errors of 
the thermometers are as great as supposed. From table 
1, however, we find: 

Table 3. Number of cases in which the total range 

of the difference, wire length minus thermometer 

depth, lies between stated limits 



Wire angle 


Limits of range in meters 


Oto 20 


21 to 40 


41 to 60 


to 5 
6 to 10 


13 3 
13 5 1 



From this compilation it is seen that the ranges are 
smaller than estimated, and this result leads to the con- 
clusion that the accuracy of the temperature determina- 
tions is greater than supposed. 

Grouping the differences and ranges according to the 
depths to which the thermometers have been used, we 
find the values which are entered in table 4. 



Table 4. Differences between wire length and thermometer depth, and total 
ranges of these differences 



Mean depth 



Number of 
thermometers 



Number of 
observations 



Mean 
difference 
in meters 



Maximum 
range 







Wire angle 0° to 5° 






to 1000 


8 


79 


- 2.4 


21 


1000 to 2000 


6 


15 


1.6 


22 


> 2000 


6 


15 
Wire angle 6° to 10° 


- 2.4 


37 


to 1000 


16 


88 


- 1.1 


24 


1000 to 2000 


4 


19 


9.9 


31 


> 2000 


4 


30 


11.4 


45 



14 



OBSERVATIONS AND RESULTS IN PHYSICAL OCEANOGRAPHY 



From this table it is seen that the difference is inde- 
pendent of depth if the wire angle is from 0° to 5° but 
the range of the differences increases with depth as was 
expected. If the wire angle is from 6° to 10° the differ- 
ence increases with increasing wire length in agreement 
with the fact that the thermometer depth, if exactly de- 
termined, must be smaller than the wire length and the 
difference must increase with depth. In this case we 
find also that the maximum range increases with depth 
but the maximum ranges are greater than in case of the 
wire angle from 0° to 5°. The last result is easily ac- 
counted for by the fact that the curvature of the wire en- 
ters as an uncertain element if the wire angle is appre- 
ciable. 

On the basis of the preceding discussion the accura- 
cy of the thermometric determination of depth on board 



the Carnegie can be stated, assuming that the thermom- 
eters have functioned properly. Extrapolating to 6000 
meters we find: 

Depth 1000 2000 3000 4000 5000 6000 

Accuracy of 

thermometric 

determination of 

depth in meters +10 +12 



+15 +20 +25 +30 



This accuracy is highly satisfactory. It is evident 
that every uncertainty as to the depth, arising because of 
great wire angle, can be eliminated by attaching pressure 
thermometers to some of the water bottles along the 
wire. 



LITERATURE CITED 



Ennis, C.C. 1933. Hydrog. Rev., vol. 10, pp. 131-135. 

May. 
Schumacher, A. 1923. Ann. Hydrog., vol. 51, pp. 273- 

280. 
Soule, F. M. 1933. Hydrog. Rev., vol. 10, pp. 126-130. 

May. 



Wiist, G. 1932. Wissensch. Ergebn. d. Deut. Atlantischen 
Exped. auf dem Forschungs- und Vermessungschiff 
"Meteor," 1925-1927, vol. 4, Erster Teil, pp. 60- 
177. 



DETERMINATION OF DEPTHS AT WHICH TEMPERATURES WERE MEASURED 

AND WATER SAMPLES COLLECTED 



The length of the wire from the surface to the water 
bottle gives the exact depth only if conditions are so fa- , 
vorable that the wire remains vertical but if the drift of 
the vessel is great on account of surface currents or 
wind, or if considerable subsurface currents occur, the 
wire cannot be kept in a vertical position. An approxi- 
mate value of the depth of a water bottle can then be com- 
puted from the length of the wire to the bottle and the 
wire angle at the surface, assuming the latter to remain 
constant. Such computation will generally render erro- 
neous values for the depth, however, because the wire 
will, as a rule, not remain straight but will form a curve 
and the wire angle is, therefore, not constant but varies 
with depth. In most cases the wire angle decreases with 
depth and the assumption of a constant wire angle gives, 
therefore, too small values of the depth. 

The Carnegie could not be manuevered so readily 
that the wire could be kept approximately vertical under 
all conditions and great wire angles necessarily oc- 
curred. y The knowledge of the depth at which tempera- 
tures were measured and from which water samples 
were brought up would, therefore, in many instances have 
been inaccurate if this should have been derived from 
wire lengths and wire angles only. On board the Carne- 
gie , however, every second water bottle of the deep se- 
ries was provided with one unprotected and one protected 
thermometer, and by means of the indications of these 
thermometers the depths of these water bottles could be 
found with an accuracy, which, according to the results 
in a preceding section (p. 11) was about +10 meters at 
a depth of 1000 meters and +30 meters at a depth of 6000 
meters. Knowing the depth of several points of the wire 
with this accuracy, the curvature of the wire could be 
determined and the depth of the intermediate water bot- 
tles could be found. When taking the shallow series, 
down to 300 to 400 meters, two or more of the water bot- 



tles were also provided with unprotected thermometers 
and the indications of these were used for detecting any 
conspicuous deviation of the wire from a straight line. 
It was found, however, that at small depths no great er- 
rors were introduced by assuming the wire angle to re- 
main constant. 

The practical method, which was adopted for com- 
puting the depths on the basis of all available informa- 
tion, is best explained by means of an example. Table 1 
contains the data from Carnegie station 71 (latitude 11° 
57' south, longitude 78° 37' west). At this station, which 
was occupied on February 6, 1929, two series of water 
bottles were sent down. The wire angles observed on 
board are entered in the first column of the table and 
were 35° for the shallow and 40° for the deep series. 
The cosines of these angles are entered in the second 
column of the table. The third column contains the wire 
lengths to the different water bottles. Four of the seven 
water bottles of the deep series and two of the water 
bottles of the shallow series were provided with both 
protected and unprotected thermometers. From the in- 
dications of these thermometers, the depths have been 
computed which are entered in the fourth column of the 
table. The next column contains the factors by means of 
which the corresponding wire lengths must be multiplied 
in order to give these depths. These factors and the 
cosines of the wire angles have been plotted against wire 
lengths (fig. 1) and curves have been drawn representing 
the factors by means of which any wire length has to be 
multiplied in order to find the depth of that particular 
point on the wire. From the curves the factors have 
been read off for the intermediate wire lengths and en- 
tered in the fifth column of the table. The final depths 
in column six have been derived by multiplying the wire 
lengths (column three) with these factors. 

From table 1 it is seen that the ratio between the 



Table 1. Computation of depths at Carnegie station 71 (latitude 11° 57' south, longitude 78° 37' west, 
February 6, 1929) on the basis of thermometer depths and assuming the wire angle to be constant 



1 


2 


3 


4 


5 


6 


7 


8 


9 


10 




Cosine 




Ther- 








Depth 


Ob- 


Ob- 


Wire 


of 


Wire 


mom- 




Adopted 
ratio 


Adopted 


wire 


served 


served 


angle, 


wire 


length, 


eter 


Ratio 


depth, 


angle 


temper- 


salini- 


o 


angle 


meters 


depths, 






meters 


constant, 


ature, 


ties, 






meters 








meters 


°C 


°/oo 



35 



40 



0.819 



0.766 


















23.46 


35.24 


5 






0.810 


4 


4 


23.30 


35.26 


24 






0.812 


19 


20 


23.30 


35.24 


49 






0.814 


40 


40 


18.15 


35.14 


73 






0.818 


60 


60 


15.85 


35.09 


98 






0.820 


80 


80 


14.30 


35.02 


200 


157 


0.785 


0.832 


166 


164 


12.91 


34.94 


295 






0.842 


248 


242 


11.76 


34.87 


391 


333 


0.852 


0.850 


332 


320 


10.74 


34.79 


369 


296 


0.802 


0.800 


295 


283 


11.42 


34.85 


628 






0.811 


509 


481 


8.16 


34.64 


1016 


838 


0.825 


0.825 


838 


778 


5.29 


34.54 


1652 






0.847 


1399 


1265 


3.15 


34.62 


2250 


1941 


0.863 


0.863 


1941 


1724 


2.23 


34.64 


2797 






0.875 


2447 


2142 


1.87 


34.67 


3345 


2963 


0.886 


0.886 


2963 


2562 


1.81 


34.68 



15 



16 



OBSERVATIONS AND RESULTS IN PHYSICAL OCEANOGRAPHY 



wire length and the depth increases from the surface and 
down, meaning that the wire angle decreases. By means 
of the wire lengths and the actual depths of the different 
points on the wire, the curve which the wire formed at 
the time when the water bottles were reversed has been 
constructed and represented graphically in figure 2. 

The straight line which is entered in figure 2 shows 
the position which the wire would have had if the wire 
angle had remained constant. It is seen that the actual 
depth of any given point on the wire is considerably 
greater than the depth corresponding to a constant wire 
angle. This fact is also evident from column 8 in table 
1. This gives the depths which are derived by means of 
thermometer depths and wire length and the depths which 
are computed on the basis of a constant wire angle. In 
the table the observed temperatures and salinities have 
been entered. According to the values in the table, the 
temperatures and salinities were observed at greater 
depths than those which are obtained when assuming the 
wire angle to be constant. The discrepancy increases 
with depth and reaches an amount of 400 meters at a 
depth of about 2900 meters. Representing graphically 
the vertical distribution of the temperature, the temper- 
ature curve is displaced upward if the depths are de- 
rived from wire lengths and wire angle only. This ex- 
ample can be used for illustrating the importance of ac- 
curacy as to depth even when the vertical variation of 
the temperature in vertical direction is small. Station 
71 is situated within an area where the temperatures are 
very uniform below 1800 meters. In figure 3 the tem- 
peratures at stations 68 to 79 have been plotted against 
depth. For station 71 double values have been entered, 
corresponding to the adopted depths, and corresponding 
to the depths which have been derived, assuming the 



wire angle to be constant. It is seen that the former lie 
very nearly on the curve which is derived from the ob- 
servations at the other stations in this region whereas 
the latter lie off this curve. 

From the table it is seen that the depths of observa- 
tions are always less than the wire length and thaf the 
difference increases with increasing wire length, reach- 
ing a value of 382 meters at a wire length of 3345 meters. 
These figures also demonstrate the importance of the 
direct determination of the depths at which the tempera- 
tures were measured and from which water samples 
were taken. 

A compilation of the differences between wire 
lengths and actual depths of observation has not been 
undertaken and in the tables of results (Oceanography 
I-B) only the actual depths have been entered. At the 
greater number of stations these have been determined 
accurately by means of the above method, but in some 
instances the pressure thermometers have not functioned 
properly and the depths are, therefore, doubtful. In the 
tables of results special remarks are entered in each 
such case. In this place attention shall also be called to 
the fact that overlapping values of temperature and sa- 
linity have been obtained at a number of stations at 
which the greatest depth of the shallow series has been 
selected slightly greater than the smallest depth on the 
deep series. These overlapping values do not always 
fall on a smooth curve. The reason may be that a time 
change has taken place, but the reason may also be that 
the depths are slightly in error. An inspection of the 
temperature graphs shows that errors of + 10 meters in 
the depth which as a rule would account for the discrep- 
ancies and errors of this magnitude are not excluded. 



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17 



NOTE ON THE PRACTICAL CORRECTION OF DEEP-SEA REVERSING 

THERMOMETERS AND THE DETERMINATION OF THE DEPTH OF 
REVERSAL FROM PROTECTED AND UNPROTECTED THERMOMETERS 



Because of its simplicity and its elementary char- 
acter, little has been published regarding the actual 
steps involved in the practical reduction of the readings 
of the deep-sea reversing thermometers, protected and 
unprotected, to obtain temperatures and depths. Yet, 
judging from the number of requests for such informa- 
tion, there seems to be a need for its publication. The 
aim of this article is to supply that need and no claim 
of originality is made for the following. 

In a reversing thermometer there are two correc- 
tions which must be applied. One is the index or scale 
correction, I, which arises from irregularities in the 
cross section of the capillary tube, and the other is a 
temperature-difference correction arising from the fact 
that the temperature at which the thermometer is read 
is usually different from the temperature at which it 
was reversed. The index correction is determined by 
calibration and is dependent only on the reading of the 
thermometer. As the temperature-difference correc- 
tion is a correction for expansion, however, it depends 
on both the reading of the thermometer and the temper- 
ature at which it is read. Since the exact temperature- 
difference correction involves the temperature of rever- 
sal which is unknown, the practical formula used is an 
approximation which may take various forms. In the 
Russian Oceanographical Tables, 1931, compiled by 
N. N. Subow, S. W. Boujewicz, and Was. W. Shoulejkin, 
the correction for protected thermometers has the form 



AT = [ 



fl" - t) (T' + vp) 
K [ 



[1 



(T' + v ) 
K J 



I 



where AT is the total correction, T' is the reading of 
the main thermometer, t is the reading of the auxiliary 
thermometer (the temperature at which the reversing 
thermometer is read), v is the volume of mercury in 
the thermometer after reversal at 0° C expressed as 
degrees, K is a constant depending on the relative ther- 
mal coefficient of expansion of mercury and the glass of 
which the thermometer is made, and I is the index cor- 
rection. 

In the Memoirs of the Imperial Marine Observatory 
(1932), Koji Hidaka gives the correction for protected 
thermometers as 



AT 



(T' - t) (T' + v ) 



K[l 



(T' + vp - t) 
K 



where the symbols all have the significance described 
above. 

The correction given by Schumacher (1923) is, 
using the same symbols 

AT = r (T' - t) (T' + vp) + (T' - t) + (T' + v ) + j 



K 



K 



As an unprotected thermometer is used in conjunction 
with a protected thermometer, the temperature of re- 
versal is known from the protected thermometer. The 



temperature-difference correction, in the case of an 
unprotected thermometer, is therefore more simple, 
and the total correction is 

AT = (T W - t) (T' + v ) + l 
K 

where Tw is the temperature of reversal as determined 
by the protected thermometer and where the other sym- 
bols have the same significance as before. 

The constant K is determined by the quality of the 
glass, and is 6100 for Jena 59"! and 6300 for Jena 161". 
As most deep-sea reversing thermometers are made 
from either one or the other of these kinds of glass, it 
is possible to prepare a table, based on one or the other 
of these values of K, giving the value of the temperature- 
difference correction for different values of (T' - t) and 
(T' + v ). If two tables are prepared, one for K = 6100 
and one for K = 6300, it is then possible by their use to 
correct any protected thermometer whose index correc- 
tion has been determined. Similar tables may also be 
prepared for unprotected thermometers, but such tables 
should give the correction for different values of (Tw -t) 
and (T' + Vo). Such tables may be converted into graphi- 
cal form. 

The time required at sea for reducing observations, 
however, is greatly lessened by the preparation ashore 
of complete correction graphs for individual thermome- 
ters. Such graphs may be constructed as follows: If C 
represents the temperature-difference correction, we 
have from Schumacher's formula for protected ther- 
mometers given above 



c = (T'-t)(T' + v ) + 
K 



or, rearranging 



(T'-t)(T' + Vo) 2 +(T'-t)2(T' + v ) 
K2 



(r . t) 2(I^l t(T , t)[ (T^oM(fM ) ]-Cs0 



whence 



, T , rt fl" + vo + K) -. / (T' + v + K)2 ~ K2 

U " l) 2 + V 4 + (T' + v ) 

Now if the radical of the right-hand member of the above 
equation is expanded by the binomial theorem, we have 



(T'-- t) = 



K 4 



K2 



(T' + vo + K) (T' + v ) 



C - 



rC^ + 



2K6 



(T' + v +K)3(T' + Vo)2 + (T'+v +K)5(T' + v ) 3 



C3.. 



Now T' is assigned a selected value near one ex- 
treme of the range of the thermometer and (T' - t) is 
evaluated as C is assigned different values in steps of 0.01 
from 0.00 to such a figure aSwill give the temperature 



19 



20 



OBSERVATIONS AND RESULTS IN PHYSICAL OCEANOGRAPHY 



difference (T' - t) as large a value as is necessary to 
cover the anticipated conditions. Except in restricted 
environments (such as polar summers) this value of 
(T' - t) will proi ibly be about 30° since water tempera- 
tures as low as about 0° may be expected, and reading 
temperatures as high as 30° are common. The process 
is then repeated with T' assigned an even-degree value 
near the other extreme of the range of the thermometer. 
For most thermometers, the first two terms on the 
right-hand side of the above equation determine the 
value of (T' - t) with sufficient accuracy. 

The correction graph may now be constructed on 
cross-section paper with the readings of the reversing 
thermometer (T') as ordinates and the corrected read- 
ings of the auxiliary thermometer (t) as abscissae. A 
convenient scale is 0.°1 to the millimeter. The length of 
the plotting sheet should be somewhat longer than three 
times the length of the finished graph which will occupy 
approximately the middle third of the original plotting 
sheet. On this graph the line of zero correction will be 
a 45° -line through all points of T' = t. This line is 
drawn lightly through those values of T' for which the 
index correction is known. 

The values of (T' - t) computed as mentioned above, 
are then laid off as points measured from the zero-cor- 
rection line along the appropriate T' lines, one near the 
upper edge and one near the lower edge of the graph. 
These points are laid off in both directions from the zero- 
correction line since the correction may have either 
sign. Straight lines approximately parallel to the zero- 
correction line, representing lines of equal temperature- 
difference correction, are then drawn lightly through 
those values of T' for which the index correction is 
known. The graph would now be complete if there were 
no index corrections, but the lines must be shifted either 
to the right or to the left at all values of T' where the 
index correction is not zero. Thus, if at 0° the index 
correction is +0.°01, the zero-correction line as well as 
all the other correction lines at T' = 0° are shifted one 
line (or 0.°01 correction) to the right. When these shifts 
have been made to accommodate all known index correc- 
tions, the resulting graph consists of a number of zigzag 
lines, all approximately parallel and having an approxi- 
made 45 '-trend. The correction lines exterior to the 
required range of T' and t may now be cut off and the 
graph is ready for use. A specimen correction graph is 
shown in figure 1. 

As described above, the lines of equal correction 
for temperature difference between reversal and reading 
are assumed to be straight. As this assumption is not 
exactly true, an error is introduced. This error is 
greater, the greater the interval between the two values 
of T' for which the points are computed, and is greater, 
the greater the numerical value of (T' - t). As an exam- 
ple of the magnitude of this error, let us take a graph 
for a thermometer whose range is 0° to +20° C and pre- 
pared for a maximum value of t = 30° C. In .this case 
the maximum error in the graph will occur in the neigh- 
borhood of T' = 10° and t = 30° where the error will be 
approximately 0.003° C. Such an error is not usually 
significant, but if greater accuracy is desired the values 
of (T' - t) can be computed for intervening values of T', 
thus breaking the single straight lines into two or more 
parts. Because of the increased labor required in this 
procedure and the small magnitude of the error involved, 
the refinement is not recommended. 



In the case of unprotected thermometers, where C 
is again the temperature-difference correction 



(T w - t) 



CK 



(T' + v ) 



As with the protected thermometers, the temperature 
difference (Tw - t) is evaluated for a series of C which 
is varied in steps of 0.°01 and the computations carried 
through for two extreme values of T'. Now, however, a 
plot of (T w - t) against T' is to be prepared but is car- 
ried out in much the same manner as the previously 
described plot of T' against t, the index correction shifts 
being made as before. 

Having determined the corrected readings of a pro- 
tected thermometer and its accompanying unprotected 
thermometer, the depth at which they were reversed 
can be computed from the formula 

D _ (T U - T) 
QPm 

where D is the depth in meters, T u is the corrected 
reading of the unprotected thermometer, T is the true 
temperature given by the corrected reading of the pro- 
tected thermometer, Q is the pressure constant of the 
unprotected thermometer or the change in number of 
degrees in the corrected reading of the unprotected 
thermometer produced by a change in pressure of one- 
tenth kilogram per square centimeter, and p m is the 
mean specific gravity of the water column above the 
thermometers when they were reversed. The constant 
Q is of the order of magnitude of 0.01 and is given in the 
thermometer certificate, usually in the form of the de- 
grees change in reading per kilogram per square centi- 
meter change in pressure. 

The approximate depth of the various water bottles 
and thermometers will be known from the wire angle 
and the readings of the meter wheel. From the correct- 
ed temperatures and the salinity measurements, the 
density (crt) of the water samples can be determined 
from Knudsen's "Hydrographical tables." Knowing 
these values, the values of density in situ (cr^) are de- 
termined by applying three corrections, each of which 
is given in tabular form in Hesselberg and Sverdrup's 
paper in Bergens Museums Aarbok, 1914-1915. The 
most important of these corrections is a function of 
depth, and since the exact depth of the samples is un- 
known the resulting values of density in situ will be only 
approximate. These values are then plotted against 
their approximate depths, a curve drawn, and a value of 
the mean density scaled from the curve at half the ap- 
proximate depth. It is to be remembered that this density- 
depth chart is constructed solely for the purpose of de- 
termining a mean density which is to be used as a factor 
in the reduction of thermometer depths. It is only nec- 
essary to determine this mean density to the nearest 
unit in the third decimal place; for example, to know 
that the mean density is 1.034 rather than 1.033 or 
1.035. In terms of 0"tD this would mean the nearest unit. 
As the order of magnitude of depth variation of ctD is 
about one unit per 200 meters, it is easily seen that the 
density-depth curve need not be very accurate, ^fter 
the adjusted depths of the samples have been determined 
in this manner, and the vertical distribution curves of 
salinity and temperature have been drawn, these may be 



CORRECTION OF THERMOMETERS AND DETERMINATION OF DEPTH OF REVERSAL 



21 



scaled for salinity and temperature at selected depths 
and values of a^ computed for these depths. The values 
of <rtD so derived may then be used to construct a more 
accurate density-depth curve which can be used to check 
the values of mean density used in the reduction of the 
thermometer depths. If the values do not check within 
the limits mentioned above, a second approximation 
must be made, but this will rarely be necessary. 

From the foregoing it will be seen that one meter in 
depth corresponds to a difference of about 0.°01 C be- 
tween the corrected readings of the protected and unpro- 
tected thermometers. Experience has shown that unpro- 



tected thermometers having a range of about 60° C 
divided into 1/5° can be read with an accuracy of better 
than 0.°01. Comparisons of thermometer depths with 
depths determined by wire length when the wire angle 
was small indicate that the method gives depths reliable 
to within about +10 meters. The use of unprotected ther- 
mometers at intervals along the length of a wire to which 
a number of water bottles is attached, in conjunction 
with meter -wheel readings, thus provides a satisfactory 
method of determining the depths of all the water bottles 
on the wire. 



Hidaka, K. 1932. Mem. Imp. Marine Obs. Vol. 5, no. 1, 
p. 11. Kobe, Japan. 



LITERATURE CITED 

Schumacher, A. 1923. Ann. Hydrogr. Vol. 51, p. 273. 





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22 



NOTE ON COMPUTATION OF DENSITY OF SEA WATER AND ON 
CORRECTIONS FOR DEEP-SEA REVERSING THERMOMETERS 



In the reductions of the oceanographic observations 
made on board the Carnegie during her seventh cruise, 
it was fqund necessary to devise methods by which the 
great amount of computational work involved might be 
simplified and reduced. 

A considerable part of this work was the determi- 
nation of the density of sea water from its values of sa- 
linity and temperature, for which purpose special tables 
were prepared in the Department of Terrestrial Mag- 
netism. 

Table 1 is a table prepared for computing the den- 
sity, t, being based on the formula 

<rt = St + (cr + 0.1324) [1 - A t + B t (cr - 0.1324)] (1) 

together with the values of the involved constants as 
given in Knudsen's "Hydrographical tables." 

Experience has proved the table more satisfactory 
than graphs because of the more or less unwieldy graphs 
resulting from the scale requirements imposed by the 
requisite degree of refinement. 

Table 2 gives the corrections for depth and temper- 
ature and for depth and salinity necessary to reduce the 
values of density, cr t , to those in situ, cr tD . it is a 
modification of the tables of Hesselberg and Sverdrup to 
the extent that the separate corrections for depth and 
for temperature of the latter tables have been combined, 
thus reducing the number of entries from three to two. 

A similar modification was made of the Hesselberg 
and Sverdrup correction tables for computing specific 
volume and dynamic depth. 

The accompanying graph (fig. 1) was devised for 
determining the corrections for unprotected deep-sea 
reversing thermometers. It is based on the formula for 
correction 



At 



(T w + v ) (T' - t) 
K 



(2) 



in which T w is the recorded temperature of the unpro- 
tected thermometer, T' the recorded temperature of 
main thermometer, t is the recorded temperature (cor- 
rected) of auxiliary thermometer, v is the volume of 
broken-off column of mercury at 0°, and K the coeffi- 
cient of expansion of the glass (Jena 59iii for the ther- 
mometers used on the Carnegie , for which K = 6100). 

Because of the large number of thermometers used 
in the Carnegie observations, it was not deemed expedi- 
ent to use graphs for obtaining the corrections for the 
protected thermometers, since, because of the different 
values of v , it would have been necessary to construct 
a graph for each thermometer. 

Instead a table, of which table 3 is a specimen sheet, 
was prepared which covered all the Carnegie values of 
the tabular arguments and was based on the formula for 
correction 



(T'+Vo)(T'-t) T' + v 

At = - — + I + 



K 



K 



(T'+v )(T'-t) 



K 



+ 1 



(3) 



T' and t denoting, respectively, the recorded tempera- 
tures of the main and auxiliary thermometers, I denoting 
the index correction of the main thermometer, and v 
and K having the same significance as in equation (2). 
Making K = 6100, equation (3) reduces to 



At = 0.000164 (T' + v ) (T' - t) [1 + 0.000164 (T' + v )] 
+ I + 0.000164 I (T' + v ) (4) 



The first term of the right-hand member of (4) is repre- 
sented by the tabular values in table 3, hence At = tabu- 
lar value + I + 0.000164 I (T' + v ). The term 0.000164 
I (T' + vo), may be considered negligible for well-made 
thermometers for which I does not exceed 0.°10. 



23 



24 



OBSERVATIONS AND RESULTS IN PHYSICAL OCEANOGRAPHY 



Table 1. For computing density, a, of sea water for various values of salinity, S, and of temperature, t 

Tabular values give excess of density over unity in units of fifth decimal: thus for S = 34.2 °/oo 

and t = 4f55 C, density is 1.02711 



Tem- 










Salinity, S, in 


%o 










pera- 
























ture, t 


34.0 


34.1 


34.2 


34.3 


34.4 


34.5 


34.6 


34.7 


34.8 


34.9 


35.0 


o 

-2.00 


2739 


2747 


2755 


2763 


2772 


2780 


2789 


2797 


2804 


2812 


2820 


-1.95 


39 


47 


55 


63 


71 


80 


88 


96 


04 


12 


20 


-1.90 


39 


47 


55 


63 


71 


79 


87 


96 


04 


12 


20 


-1.85 


39 


47 


55 


63 


71 


79 


87 


95 


04 


12 


20 


-1.80 


39 


47 


55 


63 


71 


79 


87 


95 


03 


12 


20 


-1.75 


38 


46 


55 


63 


71 


79 


87 


95 


03 


11 


19 


-1.70 


38 


46 


54 


63 


71 


79 


87 


95 


03 


11 


19 


-1.65 


38 


46 


54 


62 


71 


79 


87 


95 


03 


11 


19 


-1.60 


38 


46 


54 


62 


70 


78 


87 


95 


03 


11 


19 


-1.55 


38 


46 


54 


62 


70 


78 


86 


95 


03 


11 


19 


-1.50 


2738 


2746 


2754 


2762 


2770 


2778 


2786 


2794 


2802 


2811 


2819 


-1.45 


38 


46 


54 


62 


70 


78 


86 


94 


02 


10 


19 


-1.40 


37 


46 


54 


62 


70 


78 


86 


94 


02 


10 


18 


-1.35 


37 


45 


53 


62 


70 


78 


86 


94 


02 


10 


18 


-1.30 


37 


45 


53 


61 


69 


78 


86 


94 


02 


10 


18 


-1.25 


37 


45 


53 


61 


69 


77 


86 


94 


02 


10 


18 


-1.20 


37 


45 


53 


61 


69 


77 


85 


93 


02 


10 


18 


-1.15 


37 


45 


53 


61 


69 


77 


85 


93 


01 


09 


18 


-1.10 


37 


45 


53 


61 


69 


77 


85 


93 


01 


09 


17 


-1.05 


36 


45 


53 


61 


. 69 


77 


85 


93 


01 


09 


17 


-1.00 


2736 


2744 


2752 


2761 


2769 


2777 


2785 


2793 


2801 


2809 


2817 


-0.95 


36 


44 


52 


60 


68 


76 


85 


93 


01 


09 


17 


-0.90 


36 


44 


52 


60 


68 


76 


84 


92 


00 


09 


17 


-0.85 


36 


44 


52 


60 


68 


76 


84 


92 


00 


08 


16 


-0.80 


35 


43 


52 


60 


68 


76 


84 


92 


00 


08 


16 


-0.75 


35 


43 


51 


59 


67 


76 


84 


92 


00 


08 


16 


_r -'■ 


35 


43 


51 


59 


67 


75 


83 


91 


00 


08 


16 


~i ':j 


35 


43 


51 


59 


67 


75 


83 


91 


2799 


0" 


15 


-0.60 


35 


43 


51 


59 


67 


75 


83 


91 


99 


07 


15 


-0.55 


35 


42 


51 


59 


67 


75 


83 


91 


99 


07 


15 


-0.50 


2734 


2742 


2750 


2758 


2766 


2774 


2783 


2791 


2799 


2807 


2815 


-0.45 


34 


42 


50 


58 


66 


74 


82 


90 


98 


07 


15 


-0.40 


34 


42 


50 


58 


66 


74 


82 


90 


98 


06 


14 


-0.35 


34 


42 


50 


58 


66 


74 


82 


90 


98 


06 


14 


-0.30 


33 


41 


49 


57 


66 


74 


82 


90 


98 


06 


14 


-0.25 


33 


41 


49 


57 


65 


73 


81 


89 


98 


06 


14 


-0.20 


33 


41 


49 


57 


65 


73 


81 


89 


97 


05 


13 


-0.15 


33 


41 


49 


57 


65 


73 


81 


89 


97 


05 


13 


-0.10 


32 


40 


49 


57 


65 


73 


81 


89 


97 


05 


13 


-0.05 


32 


40 


48 


56 


64 


72 


81 


89 


97 


05 


13 


0.00 


2732 


2740 


2748 


2756 


2764 


2772 


2780 


2788 


2796 


2805 


2813 


0.05 


32 


40 


48 


56 


64 


72 


80 


88 


96 


04 


12 


0.10 


31 


39 


48 


56 


64 


72 


80 


88 


96 


04 


12 


0.15 


31 


39 


47 


55 


63 


71 


79 


87 


96 


04 


12 


0.20 


31 


39 


47 


55 


63 


71 


79 


87 


95 


03 


11 


0.25 


31 


39 


47 


55 


63 


71 


79 


87 


95 


03 


11 


0.30 


30 


38 


46 


54 


62 


71 


79 


87 


95 


03 


11 


0.35 


30 


38 


46 


54 


62 


70 


78 


86 


94 


02 


10 


0.40 


30 


38 


46 


54 


62 


70 


78 


86 


94 


02 


10 


0.45 


29 


37 


46 


54 


62 


70 


78 


86 


94 


02 


10 


0.50 


2729 


2737 


2745 


2753 


2761 


2770 


2777 


2785 


2793 


2802 


2810 


0.55 


29 


37 


45 


53 


61 


69 


77 


85 


93 


01 


09 


0.60 


29 


37 


45 


53 


61 


69 


77 


85 


93 


01 


09 


0.65 


28 


36 


44 


52 


60 


69 


77 


85 


93 


01 


09 


0.70 


28 


36 


44 


52 


60 


68 


76 


84 


92 


00 


08 


0.75 


28 


36 


44 


52 


60 


68 


76 


84 


92 


00 


08 


0.80 


27 


35 


43 


51 


59 


68 


76 


84 


92 


00 


08 


0.85 


27 


35 


43 


51 


59 


67 


75 


83 


91 


2799 


08 


0.90 


27 


35 


43 


51 


59 


67 


75 


83 


91 


99 


07 


0.95 


27 


35 


43 


51 


59 


67 


75 


83 


91 


99 


• 07 


1.00 


2726 


2734 


2742 


2750 


2758 


2766 


2774 


2783 


2791 


2799 


2807 


1.05 


26 


34 


42 


50 


58 


66 


74 


82 


90 


98 


06 


1.10 


26 


34 


42 


50 


58 


66 


74 


82 


90 


98 


06 


1.15 


25 


33 


41 


49 


57 


65 


73 


81 


89 


97 


06 


1.20 


25 


33 


41 


49 


57 


65 


73 


81 


89 


97 


05 



DENSITY OF SEA WATER AND CORRECTIONS FOR THERMOMETERS 



25 



Table 1. For computing density, a, of sea water for various values of salinity, S, 
and of temperature, t--Continued 



Tem- 










Salin 


ity, S, in 


%o 










pera- 
























ture, t 


34.0 


34.1 


34.2 


34.3 


34.4 


34.5 


34.6 


34.7 


34.8 


34.9 


35.0 


o 

1.25 


2725 


2733 


2741 


2749 


2757 


2765 


2773 


2781 


2789 


2797 


2805 


1.30 


24 


32 


40 


48 


56 


64 


72 


80 


88 


96 


04 


1.35 


24 


32 


40 


48 


56 


64 


72 


80 


88 


96 


04 


1.40 


23 


32 


40 


48 


56 


64 


72 


80 


88 


96 


04 


1.45. 


23 


31 


39 


47 


55 


63 


71 


79 


87 


95 


03 


1.50 


2723 


2731 


2739 


2747 


2755 


2763 


2771 


2779 


2787 


2795 


2803 


1.55 


22 


30 


38 


46 


54 


63 


71 


79 


87 


95 


03 


1.60 


22 


30 


38 


46 


54 


62 


70 


78 


86 


94 


02 


1.65 


22 


30 


38 


46 


54 


62 


70 


78 


86 


94 


02 


1.70 


21 


29 


37 


45 


53 


61 


69 


77 


85 


93 


01 


1.75 


21 


29 


37 


45 


53 


61 


69 


77 


85 


93 


01 


1.80 


21 


29 


37 


45 


53 


61 


69 


77 


85 


93 


01 


1.85 


20 


28 


36 


44 


52 


60 


68 


76 


84 


92 


00 


1.90 


20 


28 


36 


44 


52 


60 


68 


76 


84 


92 


00 


1.95 


20 


28 


36 


44 


52 


60 


68 


76 


84 


92 


00 


2.00 


2719 


2727 


2735 


2743 


2751 


2759 


2767 


2775 


2783 


2791 


2799 


2.05 


19 


27 


35 


43 


51 


59 


67 


75 


83 


91 


99 


2.10 


18 


26 


34 


42 


50 


58 


66 


74 


82 


90 


98 


2.15 


18 


26 


34 


42 


50 


58 


66 


74 


82 


90 


98 


2.20 


18 


26 


34 


42 


50 


58 


66 


74 


82 


90 


98 


2.25 


17 


25 


33 


41 


49 


57 


65 


73 


81 


89 


97 


2.30 


17 


25 


33 


41 


49 


57 


65 


73 


81 


89 


97 


2.35 


16 


24 


32 


40 


48 


56 


64 


72 


80 


88 


96 


2.40 


16 


24 


32 


40 


48 


56 


64 


72 


80 


88 


96 


2.45 


15 


23 


31 


39 


47 


55 


63 


71 


79 


87 


95 


2.50 


2715 


2723 


2731 


2739 


2747 


2755 


2763 


2771 


2779 


2787 


2795 


2.55 


15 


23 


31 


39 


47 


55 


63 


71 


79 


87 


95 


2.60 


14 


22 


30 


38 


46 


54 


62 


70 


78 


86 


94 


2.65 


14 


22 


30 


38 


46 


54 


62 


70 


78 


86 


94 


2.70 


13 


21 


29 


37 


45 


53 


61 


69 


77 


85 


93 


2.75 


13 


21 


29 


37 


45 


53 


61 


69 


77 


85 


93 


2.80 


13 


21 


29 


37 


44 


52 


60 


68 


76 


84 


92 


2.85 


12 


20 


28 


36 


44 


52 


60 


68 


76 


84 


92 


2.90 


12 


20 


28 


36 


44 


52 


60 


68 


76 


84 


91 


2.95 


11 


19 


27 


35 


43 


51 


59 


67 


75 


83 


91 


3.00 


2711 


2719 


2727 


2735 


2743 


2751 


2759 


2767 


2775 


2783 


2791 


3.05 


10 


18 


26 


34 


42 


50 


58 


66 


74 


82 


90 


3.10 


10 


18 


26 


34 


42 


50 


58 


66 


74 


82 


90 


3.15 


09 


17 


25 


33 


41 


49 


57 


65 


73 


. 81 


89 


3.20 


09 


17 


25 


33 


41 


49 


57 


65 


73 


81 


89 


3.25 


08 


16 


24 


32 


40 


48 


56 


64 


72 


80 


88 


3.30 


08 


16 


24 


32 


40 


48 


56' 


64 


72 


80 


88 


3.35 


08 


15 


23 


31 


39 


47 


55 


63 


71 


79 


87 


3.40 


07 


15 


23 


31 


39 


47 


55 


63 


71 


79 


87 


3.45 


07 


14 


22 


30 


38 


46 


54 


62 


70 


78 


86 


3.50 


2706 


2714 


2722 


2730 


2738 


2746 


2754 


2762 


2770 


2778 


2786 


3.55 


06 


14 


22 


29 


37 


45 


53 


61 


69 


77 


85 


3.60 


05 


13 


21 


29 


37 


45 


53 


61 


69 


77 


85 


3.65 


05 


13 


21 


29 


36 


44 


52 


60 


68 


76 


84 


3.70 


04 


12 


20 


28 


36 


44 


52 


60 


68 


76 


84 


3.75 


04 


12 


20 


28 


35 


43 


51 


59 


67 


75 


83 


3.80 


03 


11 


19 


27 


35 


43 


51 


59 


67 


75 


83 


3.85 


03 


11 


19 


27 


35 


42 


50 


58 


66 


74 


82 


3.90 


02 


10 


18 


26 


34 


42 


50 


58 


66 


74 


82 


3.95 


02 


10 


18 


26 


34 


41 


49 


57 


65 


73 


81 


4.00 


2701 


2709 


2717 


2725 


2733 


2741 


2749 


2757 


2765 


2773 


2781 


4.05 


01 


09 


17 


25 


33 


40 


48 


56 


64 


72 


80 


4.10 


00 


08 


16 


24 


32 


40 


48 


56 


64 


72 


80 


4.15 


00 


08 


16 


23 


31 


39 


47 


55 


63 


71 


79 


4.20 


2699 


07 


15 


23 


31 


39 


47 


55 


63 


71 


79 


4.25 


99 


07 


14 


22 


30 


38 


46 


54 


62 


70 


78 


4.30 


98 


06 


14 


22 


30 


38 


46 


54 


62 


69 


77 


4.35 


97 


05 


13 


21 


29 


37 


45 


53 


61 


69 


77 


4.40 


97 


05 


13 


21 


29 


37 


45 


52 


60 


68 


76 


4.45 


96 


04 


12 


20 


28 


36 


44 


52 


60 


68 


76 



26 



OBSERVATIONS AND RESULTS IN PHYSICAL OCEANOGRAPHY 



Table 1. For computing density, a, of sea water for various values of salinity, S, 
and of temperature, t--Continued 



Tem- 










Salinity, S, in 


%o 










pera- 
























ture, t 


34.0 


. 34.1 


34.2 


34.3 


34.4 


34.5 


34.6 


34.7 


34.8 


34.9 


35.0 


o 

4.50 


2696 


2704 


2712 


2720 


2728 


2736 


2*743 


2751 


2759 


2767 


2775 


4.55 


95 


03 


11 


19 


27 


35 


43 


51 


59 


67 


75 


4.60 


95 


03 


11 


19 


26 


34 


42 


50 


58 


66 


74 


4.65 


94 


02 


10 


18 


26 


34 


42 


50 


58 


66 


74 


4.70 


94 


02 


10 


17 


25 


33 


41 


49 


57 


65 


73 


4.75 


93 


01 


09 


17 


25 


33 


41 


49 


57 


64 


72 


4.80 


93 


01 


08 


16 


24 


32 


40 


48 


56 


64 


72 


4.85 


92 


00 


08 


16 


24 


32 


40 


48 


55 


63 


71 


4.90 


92 


2699 


07 


15 


23 


31 


39 


47 


55 


63 


71 


4.95 


91 


99 


07 


15 


23 


31 


38 


46 


54 


62 


70 


5.00 


2690 


2698 


2706 


2714 


2722 


2730 


2738 


2746 


2754 


2762 


2770 


5.05 


90 


98 


06 


14 


22 


29 


37 


45 


53 


61 


69 


5.10 


89 


97 


05 


13 


21 


29 


37 


45 


53 


60- 


68 


5.15 


89 


97 


04 


12 


20 


28 


36 


44 


52 


60 


68 


5.20 


88 


96 


04 


12 


20 


28 


36 


43 


51 


59 


67 


5.25 


87 


95 


03 


11 


19 


27 


35 


43 


51 


59 


67 


5.30 


87 


95 


03 


11 


18 


26 


34 


42 


50 


58 


66 


5.35 


86 


94 


02 


10 


18 


26 


34 


42 


50 


57 


65 


5.40 


86 


94 


01 


09 


17 


25 


33 


41 


49 


57 


65 


5.45 


85 


93 


01 


09 


17 


25 


32 


40 


48 


56 


64 


5.50 


2684 


2692 


2700 


2708 


2716 


2724 


2732 


2740 


2748- 


2756 


2763 


5.55 


84 


92 


00 


08 


15 


23 


31 


39 


47 


55 


63 


5.60 


83 


91 


2699 


07 


15 


23 


31 


39 


46 


54 


62 


5.65 


83 


91 


98 


06 


14 


22 


30 


38 


46 


54 


62 


5.70 


82 


90 


98 


06 


14 


22 


29 


37 


45 


53 


61 


5.75 


81 


89 


97 


05 


13 


21 


29 


37 


45 


53 


60 


5.80 


81 


89 


97 


05 


12 


20 


28 


36 


44 


52 


60 


5.85 


80 


88 


96 


04 


12 


20 


28 


35 


43 


51 


59 


5.90 


80 


87 


95 


03 


11 


19 


27 


35 


43 


51 


59 


5.95 


79 


87 


95 


03 


11 


18 


26 


34 


42 


50 


58 


6.00 


2678 


2686 


2694 


2702 


2710 


2718 


2726 


2734 


2742 


2749 


2757 


6.05 


78 


86 


94 


01 


09 


17 


25 


33 


41 


49 


57 


6.10 


77 


85 


93 


01 


09 


17 


24 


32 


40 


48 


56 


6.15 


76 


84 


92 


00 


08 


16 


24 


32 


40 


47 


55 


6.20 


76 


84 


92 


2699 


07 


15 


23 


31 


39 


47 


55 


6.25 


75 


83 


91 


99 


07 


15 


22 


30 


38 


46 


54 


6.30 


74 


82 


90 


98 


06 


14 


22 


30 


38 


45 


53 


6.35 


74 


82 


90 


97 


05 


13 


21 


29 


37 


45 


53 


6.40 


73 


81 


89 


97 


05 


13 


20 


28 


36 


44 


52 


6.45 


72 


80 


88 


96 


04 


12 


20 


28 


36 


43 


51 


6.50 


2772 


2680 


2688 


2695 


2703 


2711 


2719 


2727 


2735 


2743 


2751 


6.55 


71 


79 


97 


95 


03 


11 


18 


26 


34 


42 


50 


6.60 


70 


78 


86 


94 


02 


10 


18 


26 


34 


41 


49 


6.65 


70 


78 


86 


93 


01 


09 


17 


25 


33 


41 


49 


6.70 


69 


77 


85 


93 


01 


09 


16 


24 


32 


40 


48 


6.75 


69 


76 


84 


92'. 


00 


07 


16 


24 


32 


39 


47 


6.80 


68 


76 


84 


91 


2699 


07 


15 


23 


31 


39 


47 


6.85 


67 


75 


83 


91 


99 


06 


14 


22 


30 


38 


46 


6.90 


67 


74 


82 


90 


98 


05 


14 


22 


30 


31 


45 


6.95 


66 


74 


82 


89 


97 


05 


13 


21 


29 


37 


45 


7.00 


2665 


2673 


2681 


2689 


2697 


2705 


2712 


2720 


2728 


2736 


2744 


7.05 


64 


72 


80 


88 


96 


04 


12 


20 


27 


35 


43 


7.10 


64 


72 


80 


87 


95 


03 


11 


19 


27 


35 


42 


7.15 


63 


71 


79 


87 


95 


02 


10 


18 


26 


34 


42 


7.20 


62 


70 


78 


86 


94 


02 


10 


17 


25 


33 


41 


7.25 


62 


70 


77 


85 


93 


01 


09 


17 


25 


32 


40 


7.30 


61 


69 


77 


85 


92 


00 


08 


16 


24 


32 


40 


7.35 


60 


68 


76 


84 


92 


00 


07 


15 


23 


31 


39 


7.40 


60 


67 


75 


83 


91 


2699 


07 


15 


22 


30 


38 


7.45 


59 


67 


74 


82 


90 


98 


06 


14 


22 


29 


37 


7.50 


2658 


2666 


2674 


2682 


2689 


2697 


2705 


2713 


2721 


2729 


2737 


7.55 


57 


65 


73 


81 


89 


97 


04 


12 


20 


28 


36 


7.60 


57 


64 


72 


80 


88 


96 


04 


12 


19 


27 


35 


7.65 


56 


64 


72 


79 


87 


95 


03 


11 


19 


27 


34 


7.70 


55 


63 


71 


79 


87 


94 


02 


10 


18 


26 


34 


7.75 


54 


62 


70 


78 


86 


94 


02 


09 


17 


25 


33 


7.80 


54 


62 


69 


77 


85 


93 


01 


09 


17 


24 


32 


7.85 


53 


61 


69 


77 


84 


92 


00 


08 


15 


24 


32 


7.90 


52 


60 


68 


76 


84 


92 


2699 


07 


15 


23 


31 


7.95 


52 


59 


67 


75 


83 


91 


99 


07 


14 


22 


30 



DENSITY OF SEA WATER AND CORRECTIONS FOR THERMOMETERS 



27 



Table 1. For computing density, a, of sea water for various values of salinity, S, 
and of temperature, t--Continued 



Tem- 










Salinity, S, in 


%o 










pera- 
























ture, t 


34.0 


34.1 


34.2 


34.3 


34.4 


34.5 


34.6 


34.7 


34.8 


34.9 


35.0 


8.00 


2651 


2659 


2667 


2674 


2682 


2690 


2698 


2706 


2714 


2722 


2729 


8.05 


50 


58 


66 


74 


82 


89 


97 


05 


13 


21 


29 


8.10 


49 


57 


65 


73 


81 


89 


96 


04 


12 


20 


28 


8.15 


49 


56 


64 


72 


80 


88 


96 


03 


11 


19 


27 


8.20 


48 


56 


64 


71 


79 


87 


95 


03 


11 


18 


26 


8.25 


47 


55 


63 


71 


78 


86 


94 


02 


10 


18 


26 


8.30 


46 


54 


62 


70 


78 


85 


93 


01 


09 


17 


25 


8.35 


46 


53 


61 


69 


77 


85 


93 


00 


08 


16 


24 


8.40 


45 


53 


60 


68 


76 


84 


92 


00 


07 


15 


23 


8.45 


44 


52 


60 


68 


75 


83 


91 


2649 


07 


15 


22 


8.50 


2643 


2651 


2659 


2667 


2675 


2682 


2690 


2698 


2706 


2714 


2722 


8.55 


42 


50 


58 


66 


74 


82 


89 


97 


05 


13 


21 


8.60 


42 


50 


57 


65 


73 


81 


89 


97 


04 


12 


20 


8.65 


41 


49 


57 


64 


72 


80 


88 


96 


04 


11 


19 


8.70 


40 


48 


56 


64 


71 


79 


87 


95 


03 


11 


18 


8.75 


39 


47 


55 


63 


71 


79 


86 


94 


02 


10 


18 


8.80 


39 


46 


54 


62 


70 


78 


86 


93 


01 


09 


17 


8.85 


38 


46 


54 


61 


69 


77 


85 


93 


01 


08 


16 


8.90 


37 


45 


53 


61 


68 


76 


84 


92 


00 


07 


15 


8.95 


36 


44 


52 


60 


68 


75 


83 


91 


2699 


07 


15 


9.00 


2636 


2643 


2651 


2659 


2667 


2675 


■ 2682 


2690 


2698 


2706 


2714 


9.05 


35 


43 


50 


58 


66 


74 


82 


89 


97 


05 


13 


9.10 


34 


42 


50 


57 


65 


73 


81 


89 


96 


04 


12 


9.15 


33 


41 


49 


57 


64 


72 


80 


88 


96 


03 


11 


9.20 


32 


40 


48 


56 


64 


71 


79 


87 


95 


03 


10 


9.25 


31 


39 


47 


55 


63 


71 


78 


86 


94 


02 


10 


9.30 


31 


38 


46 


54 


62 


70 


77 


85 


93 


01 


09 


9.35 


30 


38 


45 


53 


61 


69 


77 


84 


92 


00 


08 


9.40 


29 


37 


45 


52 


60 


68 


76 


84 


91 


2699 


07 


9.45 


28 


36 


44 


52 


59 


67 


75 


83 


91 


98 


06 


9.50 


2627 


2635 


2643 


2651 


2659 


2666 


2674 


2682 


2690 


2698 


2705 


9.55 


27 


34 


42 


50 


58 


66 


73 


81 


89 


97 


05 


9.60 


26 


33 


41 


49 


57 


65 


73 


80 


88 


96 


04 


9.65 


25 


33 


40 


48 


56 


64 


72 


80 


87 


95 


03 


9.70 


24 


32 


40 


47 


55 


63 


71 


79 


86 


94 


02 


9.75 


23 


31 


39 


47 


54 


62 


70 


78 


86 


93 


01 


9.80 


22 


30 


38 


46 


54 


61 


69 


77 


85 


93 


00 


9.85 


22 


29 


37 


45 


53 


61 


68 


76 


84 


92 


00 


9.90 


21 


29 


36 


44 


52 


60 


68 


75 


83 


91 


2699 


9.95 


20 


28 


36 


43 


51 


59 


67 


75 


82 


90 


98 


10.00 


2619 


2627 


2635 


2643 


2650 


2658 


2666 


2674 


2681 


2689 


2697 


10.05 


18 


26 


34 


42 


49 


57 


65 


73 


81 


88 


96 


10.10 


17 


25 


33 


41 


49 


56 


64 


72 


80 


88 


95 


10.15 


16 


24 


32 


40 


48 


55 


63 


71 


79 


87 


94 


10.20 


16 


23 


31 


39 


47 


55 


62 


70 


78 


86 


94 


10.25 


15 


23 


30 


38 


46 


54 


62 


69 


77 


85 


93 


10.30 


14 


22 


29 


37 


45 


53 


61 


68 


76 


84 


92 


10.35 


13 


21 


29 


36 


44 


52 


60 


68 


75 


83 


91 


10.40 


12 


20 


28 


36 


43 


51 


59 


67 


74 


82 


90 


10.45 


11 


19 


27 


35 


42 


50 


58 


66 


74 


81 


89 


10.50 


2610 


2618 


2626 


2634 


2642 


2649 


2657 


2665 


2673 


2680 


2688 


10.55 


09 


17 


25 


33 


41 


48 


56 


64 


72 


80 


87 


10.60 


09 


16 


24 


32 


40 


48 


55 


63 


71 


79 


86 


10.65 


08 


16 


23 


31 


39 


47 


54 


62 


70 


78 


86 


10.70 


07 


15 


22 


30 


38 


46 


54 


61 


69 


77 


85 


10.75 


06 


14 


22 


29 


37 


45 


53 


61 


68 


76 


84 


10.80 


05 


13 


21 


28 


36 


44 


52 


60 


67 


75 


83 


10.85 


04 


12 


20 


28 


35 


43 


51 


59 


67 


74 


82 


10.90 


03 


11 


19 


27 


35 


42 


50 


58 


66 


73 


81 


10.95 


02 


10 


18 


26 


34 


41 


49 


57 


65 


72 


80 


11.00 


2602 


2609 


2617 


2625 


2633 


2641 


2648 


2656 


2664 


2672 


2679 


11.05 


01 


08 


16 


24 


32 


40 


47 


55 


63 


71 


78 


11.10 


00 


08 


15 


23 


31 


39 


46 


54 


62 


70 


78 


11.15 


2599 


07 


14 


22 


30 


38 


46 


53 


61 


69 


77 


11.20 


98 


06 


14 


21 


29 


37 


45 


52 


60 


68 


76 


11.25 


97 


05 


13 


20 


28 


36 


44 


51 


59 


67 


75 


11.30 


96 


04 


12 


19 


27 


35 


43 


51 


58 


66 


74 


11.35 


95 


03 


11 


18 


26 


34 


42 


50 


57 


65 


73 


11.40 


94 


02 


10 


18 


25 


33 


41 


49 


56 


64 


72 


11.45 


93 


01 


09 


17 


24 


32 


40 


48 


55 


63 


71 



28 



OBSERVATIONS AND RESULTS IN PHYSICAL OCEANOGRAPHY 



Table 1. For computing density, <r, of sea water for various values of salinity, S, 
and of temperature, t--Continued 



Tem- 










Salinity, S, in 


%o 










pera- 
























ture, t 


34.0 


34.1 


34.2 


34.3 


34.4 


34.5 


34.6 


34.7 


34.8 


34. D 


35.0 


11.50 


2592 


2600 


2608 


2616 


2623 


2631 


2639 


2647 


2655 


2662 


2670 


11.55 


92 


2599 


07 


15 


23 


30 


38 


46 


54 


81 


69 


11.60 


91 


98 


06 


14 


22 


29 


37 


45 


53 


60 


68 


11.65 


90 


97 


05 


13 


21 


28 


36 


44 


52 


60 


67 


11.70 


89 


96 


04 


12 


20 


28 


35 


43 


51 


59 


66 


11.75 


88 


96 


03 


11 


19 


27 


34 


42 


50 


58 


65 


11.80 


87 


95 


02 


10 


18 


26 


33 


,41 


49 


57 


64 


11.85 


86 


94 


01 


09 


17 


25 


32 


40 


48 


56 


64 


11.90 


85 


93 


01 


08 


16 


24 


32 


39 


47 


55 


63 


11.95 


84 


92 


00 


07 


15 


23 


31 


38 


46 


54 


62 


12.00 


2583 


2591 


2599 


2606 


2614 


2622 


2630 


2637 


2645 


2653 


2661 


12.05 


82 


90 


98 


05 


13 


21 


29 


37 


44 


52 


60 


12.10 


81 


89 


97 


05 


12 


20 


28 


36 


43 


51 


59 


12.15 


80 


88 


96 


04 


11 


19 


27 


35 


42 


50 


58 


12.20 


79 


87 


95 


03 


10 


18 


26 


34 


41 


49 


57 


12.25 


78 


86 


94 


02 


09 


17 


25 


33 


40 


48 


56 


12.30 


77 


85 


93 


01 


08 


16 


24 


32 


39 


47 


55 


12.35 


76 


84 


92 


00 


07 


15 


23 


31 


38 


46 


54 


12.40 


75 


83 


91 


2599 


06 


14 


22 


30 


37 


45 


53 


12.45 


74 


82 


90 


98 


05 


13 


21 


29 


36 


44 


52 


12.50 


2573 


2581 


2589 


2597 


2604 


2612 


2620 


2628 


2635 


2643 


2651 


12.55 


73 


80 


88 


96 


03 


11 


19 


27 


34 


42 


50 


12.60 


72 


79 


87 


95 


02 


10 


18 


26 


33 


41 


49 


12.65 


71 


78 


86 


94 


02 


09 


17 


25 


32 


40 


48 


12.70 


70 


77 


85 


93 


01 


08 


16 


24 


32 


39 


47 


12.75 


69 


76 


84 


92 


00 


07 


15 


23 


31 


38 


46 


12.80 


68 


75 


83 


91 


2599 


06 


14 


22 


30 


37 


45 


12.85 


67 


74 


82 


90 


98 


05 


13 


21 


29 


36 


44 


12.90 


66 


73 


81 


89 


97 


04 


12 


20 


28 


35 


43 


12.95 


65 


72 


80 


88 


96 


03 


11 


19 


27 


34 


42 


13.00 


2564 


2571 


2579 


2587 


2595 


2602 


2610 


2618 


2626 


2633 


2641 


13.05 


63 


70 


78 


86 


94 


01 


09 


17 


25 


32 


40 


13.10 


62 


69 


77 


85 


93 


00 


08 


16 


24 


31 


39 


13.15 


61 


68 


76 


84 


92 


2599 


07 


15 


23 


30 


38 


13.20 


60 


67 


75 


83 


91 


98 


06 


14 


22 


29 


37 


13.25 


59 


66 


74 


82 


90 


97 


05 


13 


20 


28 


36 


13.30 


58 


65 


73 


81 


89 


96 


04 


12 


19 


27 


35 


13.35 


57 


64 


72 


80 


88 


95 


03 


11 


18 


26 


34 


13.40 


56 


63 


71 


79 


86 


94 


02 


10 


17 


25 


33 


13.45 


55 


62 


70 


78 


85 


93 


01 


09 


16 


24 


32 


13.50 


2554 


2561 


2569 


2577 


2584 


2592 


2600 


2608 


2615 


2623 


2631 


13.55 


53 


60 


68 


76 


83 


91 


2599 


07 


14 


22 


30 


13.60 


52 


59 


67 


75 


82 


90 


98 


06 


13 


21 


29 


13.65 


51 


58 


66 


74 


81 


89 


97 


05 


12 


20 


28 


13.70 


49 


57 


65 


73 


80 


88 


96 


04 


11 


19 


27 


13.75 


48 


56 


64 


72 


79 


87 


95 


03 


10 


18 


26 


13.80 


47 


55 


63 


71 


78 


86 


94 


01 


09 


17 


25 


13.85 


46 


54 


62 


70 


77 


85 


93 


00 


08 


16 


24 


13.90 


45 


53 


61 


69 


76 


84 


92 


2599 


07 


15 


23 


13.95 


44 


52 


60 


68 


75 


83 


91 


98 


06 


14 


22 


14.00 


2543 


2551 


2559 


2567 


2574 


2582 


2590 


2597 


2605 


2613 


2620 


14.05 


42 


50 


58 


65 


73 


81 


89 


96 


04 


12 


19 


14.10 


41 


49 


57 


64 


72 


80 


88 


95 


03 


11 


18 


14.15 


40 


48 


56 


63 


71 


79 


86 


94 


02 


10 


17 


14.20 


39 


47 


55 


62 


70 


78 


85 


93 


01 


08 


16 


14.25 


38 


46 


53 


61 


69 


77 


84 


92 


00 


07 


15 


14.30 


37 


45 


52 


60 


68 


76 


83 


91 


2599 


06 


14 


14.35 


36 


44 


51 


59 


67 


74 


82 


90 


98 


05 


13 


14.40 


35 


43 


50 


58 


66 


73 


81 


89 


96 


04 


12 


14.45 


34 


41 


49 


57 


65 


72 


80 


88 


95 


03 


11 


14.50 


2533 


2540 


2548 


2556 


2564 


2571 


2579 


2587 


2594 


2602 


2610 


14.55 


32 


39 


47 


55 


62 


70 


78 


86 


93 


01 


09 


14.60 


31 


38 


46 


54 


61 


69 


77 


84 


92 


00 


08 


14.65 


29 


37 


45 


53 


60 


68 


76 


83 


91 


2599 


07 


14.70 


28 


36 


44 


52 


59 


67 


75 


82 


90 


98 


05 


14.75 


27 


35 


43 


50 


58 


66 


74 


81 


89 


97 


04 


14.80 


26 


34 


42 


49 


57 


65 


72 


80 


88 


96 


03 


14.85 


25 


33 


41 


48 


56 


64 


71 


79 


87 


95 


02 


14.90 


24 


32 


40 


47 


55 


63 


70 


78 


86 


93 


01 


14.95 


23 


31 


38 


46 


54 


62 


69 


77 


85 


92 


00 



DENSITY OF SEA WATER AND CORRECTIONS FOR THERMOMETERS 



29 



Table 1. For computing density, cr, of sea water for various values of salinity, S, 
and of temperature, t--Continued 



Tem-* 










Salinity, S, in 


%o 










P6P3,- 
























ture, t 


34.0 


34.1 


34.2 


34.3 


34.4 


34.5 


34.6 


34.7 


34.8 


34.9 


35.0 




15.00 


2522 


2530 


2537 


2545 


2553 


2561 


2568 


2576 


2584 


2591 


2599 


15.05 


21 


29 


36 


44 


52 


59 


67 


75 


82 


90 


98 


15.10 


20 


28 


35 


43 


51 


58 


66 


74 


81 


89 


97 


15.15 


19 


26 


34 


42 


49 


57 


65 


73 


80 


88 


96 


15.20 


18 


25 


33 


41 


48 


56 


64 


71 


79 


87 


95 


15.25 


16 


24 


32 


40 


47 


55 


63 


70 


78 


86 


93 


15.30 


15 


23 


31 


38 


46 


54 


62 


69 


77 


85 


92 


15.35 


14 


22 


30 


37 


45 


53 


60 


68 


76 


83 


91 


15.40 


13 


21 


29 


36 


44 


52 


59 


67 


75 


82 


90 


15.45 


12 


20 


27 


35 


43 


50 


58 


66 


74 


81 


89 


15.50 


2511 


2519 


2526 


2534 


2542 


2549 


2557 


2565 


2572 


2580 


2588 


15.55 


10 


17 


25 


33 


41 


48 


56 


64 


71 


79 


87 


15.60 


09 


16 


24 


32 


39 


47 


55 


63 


70 


78 


86 


15.65 


08 


15 


23 


31 


38 


46 


54 


61 


69 


77 


84 


15.70 


06 


14 


22 


30 


37 


45 


53 


60 


68 


76 


83 


15.75 


05 


13 


21 


28 


36 


44 


51 


59 


67 


74 


82 


15.80 


04 


12 


20 


27 


35 


43 


50 


58 


66 


73 


81 


15.85 


03 


11 


18 


26 


34 


42 


49 


57 


65 


72 


80 


15.90 


02 


10 


17 


25 


33 


40 


48 


56 


63 


71 


79 


15.95 


01 


09 


16 


24 


32 


39 


47 


55 


62 


70 


78 


16.00 


2500 


2507 


2515 


2523 


2530 


2538 


2546 


2554 


2561 


2569 


2577 


16.05 


2499 


06 


14 


22 


29 


37 


45 


52 


60 


68 


75 


16.10 


97 


05 


13 


20 


28 


36 


44 


51 


59 


67 


74 


16.15 


96 


04 


12 


19 


27 


35 


42 


50 


58 


65 


73 


16.20 


95 


03 


11 


18 


26 


34 


41 


49 


57 


64 


72 


16.25 


94 


02 


09 


17 


25 


32 


40 


48 


55 


63 


71 


16.30 


93 


01 


08 


16 


24 


31 


39 


47 


54 


62 


70 


16.35 


92 


2499 


07 


15 


22 


30 


38 


45 


53 


61 


68 


16.40 


91 


98 


06 


14 


21 


29 


37 


44 


52 


60 


67 


16.45 


89 


97 


05 


12 


20 


28 


35 


43 


51 


58 


66 


16.50 


2488 


2496 


2504 


2511 


2519 


2527 


2534 


2542 


2550 


2557 


2565 


16.55 


87 


95 


02 


10 


18 


25 


33 


41 


48 


56 


64 


16.60 


86 


94 


01 


09 


17 


24 


32 


40 


47 


55 


63 


16.65 


85 


92 


00 


08 


15 


23 


31 


38 


46 


54 


61 


16.70 


84 


91 


2499 


07 


14 


22 


30 


37 


45 


53 


60 


16.75 


82 


90 


98 


05 


13 


21 


28 


36 


44 


51 


59 


16.80 


81 


89 


97 


04 


12 


20 


27 


35 


43 


50 


58 


16.85 


80 


88 


95 


03 


11 


18 


26 


34 


41 


49 


57 


16.90 


79 


87 


94 


02 


10 


17 


25 


33 


40 


48 


56 


16.95 


78 


85 


93 


01 


08 


16 


24 


31 


39 


47 


54 


17.00 


2477 


2484 


2492 


2500 


2507 


2515 


2523 


2530 


2538 


2546 


2553 


17.05 


75 


83 


91 


2498 


06 


14 


21 


29 


37 


44 


52 


17.10 


74 


82 


90 


97 


05 


* 13 


20 


28 


35 


43 


51 


17.15 


73 


81 


88 


96 


04 


11 


19 


27 


34 


42 


50 


17.20 


72 


79 


87 


95 


02 


10 


18 


25 


33 


41 


48 


17.25 


71 


78 


86 


94 


01 


09 


17 


24 


32 


40 


47 


17.30 


69 


77 


85 


92 


00 


08 


15 


23 


31 


38 


46 


17.35 


68 


76 


83 


91 


2499 


06 


14 


22 


29 


37 


45 


17.40 


67 


75 


82 


90 


98 


05 


13 


21 


28 


36 


44 


17.45 


66 


74 


81 


89 


96 


04 


12 


19 


27 


35 


42 


17.50 


2465 


2472 


2480 


2488 


2495 


2503 


2511 


2518 


2526 


2533 


2541 


17.55 


63 


71 


79 


86 


94 


02 


09 


17 


25 


32 


40 


17.60 


62 


70 


78 


85 


93 


00 


08 


16 


23 


31 


39 


17.65 


61 


69 


76 


84 


92 


2499 


07 


15 


22 


30 


37 


17.70 


60 


67 


75 


83 


90 


98 


06 


13 


21 


29 


36 


17.75 


59 


66 


74 


82 


89 


97 


05 


12 


20 


27 


35 


17.80 


57 


65 


73 


80 


88 


96 


03 


11 


19 


26 


34 


17.85 


56 


64 


71 


79 


87 


94 


02 


10 


17 


25 


33 


17.90 


55 


63 


70 


78 


86 


93 


01 


09 


16 


24 


31 


17.95 


54 


62 


69 


77 


84 


92 


00 


07 


15 


23 


30 


18.00 


2453 


2460 


2468 


2476 


2483 


2491 


2498 


2506 


2514 


2521 


2529 


18.05 


51 


59 


67 


74 


82 


90 


97 


05 


13 


20 


28 


18.10 


50 


58 


65 


73 


81 


88 


96 


04 


. 11 


19 


27 


18.15 


49 


57 


64 


72 


79 


87 


95 


02 


10 


18 


25 


18.20 


48 


55 


63 


71 


78 


86 


93 


01 


09 


16 


24 


18.25 


46 


54 


62 


69 


77 


85 


92 


00 


08 


15 


23 


18.30 


45 


53 


60 


68 


76 


83 


91 


2499 


06 


14 


22 


18.35 


44 


52 


59 


67 


■ 74 


82 


90 


97 


05 


13 


20 


18.40 


43 


50 


58 


66 


73 


81 


88 


96 


04 


11 


19 


18.45 


41 


49 


57 


64 


72 


80 


87 


95 


03 


10 


18 



30 



OBSERVATIONS AND RESULTS IN PHYSICAL OCEANOGRAPHY 



Table 1. For computing density, <x, of sea water for various values of salinity, S, 
and of temperature, t--Continued 



Tem- 










Salinity, S, in 


%o 










pera- 
























ture, t 


34.0 


34.1 


34.2 


34.3 


34.4 


34.5 


34.6 


34.7 


34.8 


34.9 


35.0 


18.50 


2440 


2448 


2455 


2463 


2471 


2478 


2486 


2494 


2501 


2509 


2516 


18.55 


39 


47 


54 


62 


69 


77 


85 


92 


00 


08 


15 


18.60 


38 


45 


53 


61 


68 


76 


83 


91 


2499 


06 


14 


18.65 


36 


44 


52 


59 


67 


75 


82 


90 


97 


05 


13 


18.70 


35 


43 


50 


58 


66 


73 


81 


89 


96 


04 


11 


18.75 


34 


42 


49 


57 


64 


72 


80 


87 


95 


03 


10 


18.80 


33 


40 


48 


56 


63 


71 


78 


86 


94 


01 


09 


18.85 


31 


39 


47 


54 


62 


70 


77 


85 


92 


00 


08 


18.90 


30 


38 


45 


53 


61 


68 


76 


84 


91 


2499 


06 


18.95 


29 


37 


44 


52 


59 


67 


75 


82 


90 


98 


05 


19.06 


2428 


2435 


2443 


2451 


2458 


2466 


2473 


2481 


2489 


2496 


2504 


19.05 


26 


34 


42 


49 


57 


65 


72 


80 


87 


95 


03 


19.10 


25 


33 


40 


48 


56 


63 


71 


78 


86 


94 


01 


19.15 


24 


31 


39 


47 


54 


62 


70 


77 


85 


92 


00 


19.20 


23 


30 


38 


45 


53 


61 


68 


76 


84 


91 


2499 


19.25 


21 


29 


37 


44 


52 


59 


67 


75 


82 


90 


98 


19.30 


20 


28 


35 


43 


50 


58 


66 


73 


81 


89 


96 


19.35 


19 


26 


34 


42 


49 


57 


64 


72 


80 


87 


95 


19.40 


17 


25 


33 


40 


48 


56 


63 


71 


78 


86 


94 


19.45 


16 


24 


31 


39 


47 


54 


62 


69 


77 


85 


92 


19.50 


2415 


2422 


2430 


2438 


2445 


2453 


2461 


2468 


• 2476 


2483 


2491 


19.55 


14 


21 


29 


36 


44 


52 


59 


67 


75 


82 


90 


19.60 


12 


20 


27 


35 


43 


50 


58 


66 


73 


81 


88 


19.65 


11 


19 


26 


34 


41 


49 


57 


64 


72 


79 


87 


s 19.70 


10 


17 


25 


33 


40 


48 


55 


63 


71 


78 


86 


19.75 


08 


16 


24 


31 


39 


46 


54 


62 


69 


77 


85 


19.80 


07 


15 


22 


30 


38 


45 


53 


60 


68 


76 


83 


19.85 


06 


13 


21 


29 


36 


44 


51 


59 


67 


74 


82 


19.90 


05 


12 


20 


27 


35 


43 


50 


58 


65 


73 


81 


19.95 


03 


11 


18 


26 


34 


41 


49 


56 


64 


72 


79 


20.00 


2402 


2410 


2417 


2425 


2432 


2440 


2448 


2455 


2463 


2470 


2478 


20.05 


01 


08 


16 


23 


31 


39 


46 


54 


62 


69 


77 


20.10 


2399 


07 


15 


22 


30 


37 


45 


53 


60 


68 


75 


20.15 


98 


06 


13 


21 


28 


36 


44 


51 


59 


66 


74 


20.20 


97 


04 


12 


19 


27 


35 


42 


50 


57 


65 


73 


20.25 


95 


03 


11 


18 


26 


33 


41 


49 


56 


64 


71 


20.30 


94 


02 


09 


17 


24 


32 


40 


47 


55 


62 


70 


20.35 


93 


" 00 


08 


15 


23 


31 


38 


46 


54 


61 


69 


20.40 


91 


2399 


07 


14 


22 


29 


37 


45 


52 


60 


67 


20.45 


90 


98 


05 


13 


20 


28 


36 


43 


51 


58 


66 


20.50 


2389 


2396 


2404 


2411 


2419 


2427 


2434 


2442 


2449 


2457 


2465 


20.55 


87 


95 


03 


10 


18 


25 


33 


41 


48 


56 


63 


20.60 


86 


94 


01 


09 


16 


24 


32 


39 


47 


54 


62 


20.65 


85 


92 


00 


07 


15 


23 


30 


38 


45 


53 


61 


20.70 


83 


91 


2399 


06 


14 


21 


29 


37 


44 


52 


59 


20.75 


82 


90 


97 


05 


12 


20 


28 


35 


43 


50 


58 


20.80 


81 


88 


96 


03 


11 


19 


26 


34 


41 


49 


57 


20.85 


79 


87 


95 


02 


10 


17 


25 


33 


40 


48 


55 


20.90 


78 


86 


93 


01 


08 


16 


24 


31 


39 


46 


54 


20.95 


77 


84 


92 


2399 


07 


15 


22 


30 


37 


45 


53 


21.00 


2375 


2383 


2391 


2398 


2406 


2413 


2421 


2429 


2436 


2444 


2451 


21.05 


74 


82 


89 


97 


04 


12 


20 


27 


35 


42 


50 


21.10 


73 


80 


88 


95 


03 


11 


18 


26 


33 


41 


49 


21.15 


71 


79 


86 


94 


02 


09 


17 


24 


32 


40 


47 


21.20 


70 


77 


85 


93 


00 


08 


15 


23 


31 


38 


46 


21.25 


69 


76 


84 


91 


2399 


06 


14 


22 


29 


. 37 


44 


21.30 


67 


75 


82 


90 


97 


05 


13 


20 


28 


35 


43 


21.35 


66 


73 


81 


89 


96 


04 


11 


19 


26 


34 


42 


21.40 


64 


72 


80 


87 


95 


02 


10 


18 


25 


33 


40 


21.45 


63 


71 


78 


86 


93 


01 


09 


16 


24 


31 


39 


21.50 


2362 


2369 


2377 


2384 


2392 


2400 


2407 


2415 


2422 


2430 


2438 


21.55 


60 


68 


75 


83 


91 


2398 


06 


13 


21 


29 


36 


21.60 


59 


66 


74 


82 


89 


97 


04 


12 


20 


27 


35 


21.65 


58 


65 


73 


80 


88 


95 


03 


11 


18 


26 


33 


21.70 


56 


64 


71 


79 


86 


94 


02 


09 


17 


24 


32 


21.75 


55 


62 


70 


78 


85 


93 


00 


08 


15 


23 


31 


21.80 


53 


61 


69 


76 


84 


91 


2399 


07 


14 


22 


29 


21.85 


52 


60 


67 


75 


82 


90 


98 


05 


13 


20 


28 


21.90 


51 


58 


66 


73 


81 


89 


96 


04 


11 


19 


26 


21.95 


49 


57 


64 


72 


80 


87 


95 


02 


10 


18 


25 



DENSITY OF SEA WATER AND CORRECTIONS FOR THERMOMETERS 



31 



Table 1. For computing density, <r, of sea water for various values of salinity, S, 
and of temperature, t--Continued 



Tem- 










Salinity, S, in 


°/oo 










pera- 
ture, t 


34.0 


34.1 


34.2 


34.3 


34.4 


34.5 


34.6 


34.7 


34.8 


34.9 


35.0 


22.00 


2348 


2356 


2363 


2371 


2378 


2386 


2393 


2401 


2409 


2416 


2424 


22.05 


46 


54 


62 


69 


77 


84 


92 


00 


07 


15 


22 


22.10 


45 


53 


60 


68 


75 


83 


91 


2398 


06 


13 


21 


22.15 


44 


51 


59 


66 


74 


82 


89 


97 


04 


12 


19 


22.20 


42 


50 


57 


65 


73 


80 


88 


95 


03 


10 


18 


22.25 


41 


48 


56 


64 


71 


79 


86 


94 


01 


09 


17 


22.30 


39 


47 


55 


62 


70 


77 


85 


92 


00 


08 


15 


22.35 


38 


46 


53 


61 


68 


76 


83 


91 


2399 


06 


14 


22.40 


37 


44 


52 


59 


67 


75 


82 


90 


97 


05 


12 


22.45 


35 


43 


50 


58 


65 


73 


81 


88 


96 


03 


11 


22.50 


2334 


2341 


2349 


2357 


2364 


2372 


2379 


2387 


2394 


2402 


2410 


22.55 


32 


40 


48 


55 


63 


70 


78 


85 


93 


01 


08 


22.60 


31 


39 


46 


54 


61 


69 


76 


84 


92 


2399 


07 


22.65 


30 


37 


45 


52 


60 


67 


75 


83 


90 


97 


05 


22.70 


28 


36 


43 


51 


58 


66 


74 


81 


89 


96 


04 


22.75 


27 


34 


42 


49 


57 


65 


72 


80 


87 


95 


02 


22.80 


25 


33 


40 


48 


56 


63 


71 


78 


86 


93 


01 


22.85 


24 


31 


39 


47 


54 


62 


69 


77 


84 


92 


00 


22.90 


22 


30 


38 


45 


53 


60 


68 


75 


83 


91 


2398 


22.95 


21 


29 


36 


44 


51 


59 


67 


74 


82 


89 


97 


23.00 


2320 


2327 


2335 


2342 


2350 


2358 


2365 


2373 


2380 


2388 


2395 


23.05 


18 


26 


33 


41 


48 


56 


64 


71 


79 


86 


94 


23.10 


17 


24 


32 


39 


47 


55 


62 


70 


77 


85 


92 


23.15 


15 


23 


30 


38 


46 


53 


61 


68 


76 


83 


91 


23.20 


14 


21 


29 


37 


44 


52 


59 


67 


74 


82 


90 


23.25 


12 


20 


28 


35 


43 


50 


58 


65 


73 


80 


88 


23.30 


11 


19 


26 


34 


41 


49 


56 


64 


71 


79 


87 


23.35 


L0 


17 


25 


32 


40 


47 


55 


62 


70 


78 


85 


23.40 


08 


16 


23 


31 


38 


46 


53 


61 


69 


76 


84 


23.45 


07 


14 


22 


29 


37 


44 


52 


60 


67 


75 


82 


23.50 


2305 


2313 


2320 


2328 


2335 


2343 


2351 


2358 


2366 


2373 


2381 


23.55 


04 


11 


19 


26 


34 


41 


49 


57 


64 


72 


79 


23.60 


02 


10 


17 


25 


32 


40 


48 


55 


63 


70 


78 


23.65 


01 


08 


16 


23 


31 


39 


46 


54 


61 


69 


76 


23.70 


2299 


07 


14 


22 


30 


37 


45 


52 


60 


67 


75 


23.75 


98 


05 


13 


21 


28 


36 


43 


51 


58 


66 


74 


23.80 


96 


04 


12 


19 


27 


34 


42 


49 


57 


64 


72 


23.85 


95 


03 


10 


18 


25 


33 


40 


48 


55 


63 


71 


23.90 


94 


01 


09 


16 


24 


31 


39 


46 


54 


62 


69 


23.95 


92 


00 


07 


15 


22 


30 


37 


45 


53 


60 


68 


24.00 


2291 


2298 


2306 


2313 


2321 


2328 


2336 


2344 


2351 


2359 


2366 


24.05 


89 


97 


04 


12 


19 


27 


34 


42 


50 


57 


65 


24.10 


88 


95 


03 


10 


18 


25 


33 


41 


48 


56 


63 


24.15 


86 


94 


01 


09 


16 


24 


31 


39 


47 


54 


62 


24.20 


85 


92 


00 


07 


15 


22 


30 


38 


45 


53 


60 


24.25 


83 


91 


2298 


06 


1* 


21 


28 


36 


44 


51 


59 


24.30 


82 


89 


97 


04 


12 


19 


27 


35 


42 


50 


57 


24.35 


80 


88 


95 


03 


10 


18 


25 


33 


41 


48 


56 


24.40 


79 


86 


94 


01 


09 


16 


24 


32' 


39 


47 


54 


24.45 


77 


85 


92 


00 


07 


15 


22 


30 


38 


45 


53 


24.50 


2276 


2283 


2291 


2298 


2306 


2313 


2321 


2329 


2336 


2344 


2351 


24.55 


74 


82 


89 


97 


04 


12 


19 


27 


35 


42 


50 


24.60 


73 


80 


88 


95 


03 


10 


18 


26 


33 


41 


48 


24.65 


71 


79 


86 


94 


01 


09 


16 


24 


32 


39 


47 


24.70 


70 


77 


85 


92 


00 


07 


15 


23 


30 


38 


45 


24.75 


68 


76 


83 


91 


2298 


06 


13 


21 


29 


36 


44 


24.80 


67 


74 


82 


89 


97 


04 


12 


20 


27 


35 


42 


24.85 


65 


73 


80 


88 


95 


03 


10 


18 


26 


33 


41 


24.90 


64 


71 


79 


86 


94 


01 


09 


17 


24 


32 


39 


24.95 


62 


70 


77 


85 


92 


00 


07 


15 


23 


30 


38 


25.00 


2261 


2268 


2276 


2283 


2291 


2298 


2306 


2314 


2321 


2329 


2336 


25.05 


59 


67 


74 


82 


89 


97 


04 


12 


20 


27 


35 


25.10 


58 


65 


73 


80 


88 


95 


03 


10 


18 


26 


33 


25.15 


56 


64 


71 


79 


86 


94 


01 


09 


16 


24 


32 


25.20 


55 


62 


70 


77 


85 


92 


00 


07 


15 


23 


30 


25.25 


53 


61 


68 


76 


83 


91 


2298 


06 


13 


21 


28 


25.30 


52 


59 


67 


74 


82 


89 


97 


04 


12 


19 


27 


25.35 


50 


58 


65 


73 


80 


88 


95 


03 


10 


18 


25 


25.40 


48 


56 


64 


71 


79 


86 


94 


01 


09 


16 


24 


25.45 


47 


54 


62 


70 


77 


85 


92 


00 


07 


15 


22 



32 



OBSERVATIONS AND RESULTS IN PHYSICAL OCEANOGRAPHY 



Table 1. For computing density, o", of sea water for various values of salinity, S, 
and of temperature, t- -Continued 



Tem- 










Salinity, S, ir 


%>o 










pera- 
























ture, t 


34.0 


34.1 


34.2 


34.3 


34.4 


34.5 


34.6 


34.7 


34.8 


34.9 


35.0 


25.50 


2245 


2253 


2261 


2268 


2276 


2283 


2291 


2298 


2306 


2313 


2321 


25.55 


44 


51 


59 


67 


74 


82 


89 


97 


04 


12 


19 


25.60 


42 


50 


57 


65 


73 


80 


88 


95 


03 


10 


18 


25.65 


41 


48 


56 


63 


71 


79 


86 


94 


01 


09 


16 


25.70 


39 


47 


54 


62 


69 


77 


85 


92 


00 


07 


15 


25.75 


38 


45 


53 


60 


68 


75 


83 


90 


2298 


06 


13 


25.80 


36 


44 


51 


59 


66 


74 


81 


89 


97 


04 


12 


25.85 


35 


42 


50 


57 


65 


72 


80 


87 


95 


03 


10 


25.90 


33 


41 


48 


56 


63 


71 


78 


86 


93 


01 


09 


25.95 


32 


39 


47 


54 


62 


69 


77 


84 


92 


2299 


07 


26.00 


2230 


2238 


2245 


2253 


2260 


2268 


2275 


2283 


2290 


2298 


2305 


26.05 


29 


36 


44 


51 


59 


66 


74 


81 


89 


96 


04 


26.10 


27 


34 


42 


50 


57 


65 


72 


80 


87 


95 


02 


26.15 


25 


33 


40 


48 


55 


63 


71 


78 


86 


93 


01 


26.20 


24 


31 


39 


46 


54 


61 


69 


77 


84 


92 


2299 


26.25 


22 


30 


37 


45 


52 


60 


67 


75 


82 


90 


98 


26.30 


21 


28 


36 


43 


51 


58 


66 


73 


81 


88 


96 


26.35 


19 


27 


34 


42 


49 


57 


64 


72 


79 


87 


94 


26.40 


18 


25 


33 


40 


48 


55 


63 


70 


78 


85 


93 


26.45 


16 


23 


31 


39 


46 


54 


61 


69 


76 


84 


91 


26.50 


2214 


2222 


2229 


2237 


2244 


2252 


2260 


2267 


2275 


2282 


2290 


26.55 


13 


20 


28 


35 


43 


50 


58 


65 


73 


81 


88 


26.60 


11 


19 


26 


34 


41 


49 


56 


64 


71 


79 


87 


26.65 


10 


17 


25 


32 


40 


47 


55 


62 


70 


77 


85 


26.70 


08 


16 


23 


31 


38 


46 


53 


61 


68 


76 


83 


26.75 


07 


14 


22 


29 


37 


44 


52 


59 


67 


74 


82 


26.80 


05 


12 


20 


28 


35 


43 


50 


58 


65 


73 


80 


26.85 


03 


11 


18 


26 


34 


41 


49 


56 


64 


71 


79 


26.90 


02 


09 


17 


24 


32 


39 


47 


54 


62 


70 


77 


26.95 


00 


08 


15 


23 


30 


38 


45 


53 


60 


68 


75 


27.00 


2199 


2206 


2214 


2221 


2229 


2236 


2244 


2251 


2259 


2266 


2274 


27.05 


97 


05 


12 


20 


27 


35 


42 


50 


57 


65 


72 


27.10 


95 


03 


10 


18 


26 


33 


41 


48 


56 


63 


71 


27.15 


94 


01 


09 


16 


24 


31 


39 


46 


54 


62 


69 


27.20 


92 


00 


07 


15 


22 


30 


37 


45 


52 


60 


67 


27.25 


91 


2198 


06 


13 


21 


28 


36 


43 


51 


58 


66 


27.30 


89 


97 


04 


12 


19 


27 


34 


42 


49 


57 


64 


27.35 


87 


95 


02 


10 


17 


25 


32 


40 


47 


55 


63 


27.40 


86 


93 


01 


08 


16 


23 


31 


38 


46 


53 


61 


27.45 


84 


92 


2199 


07 


14 


22 


29 


37 


44 


52 


59 


27.50 


2183 


2190 


2198 


2205 


2213 


2220 


2228 


2235 


2243 


2250 


2258 


27.55 


81 


88 


96 


03 


11 


19 


26 


34 


41 


49 


56 


27.60 


79 


87 


94 


02 


09 


17 


24 


32 


39 


47 


54 


27.65 


78 


85 


93 


00 


08 


15 


23 


30 


38 


45 


53 


27.70 


76 


84 


91 


2199 


06 


14 


21 


29 


36 


44 


51 


27.75 


74 


82 


90 


97 


05 


12 


20 


27 


35 


42 


50 


27.80 


73 


80 


88 


95 


03 


10 


18 


25 


33 


41 


48 


27.85 


71 


79 


86 


94 


01 


09 


16 


24 


31 


39 


46 


27.90 


70 


77 


85 


92 


00 


07 


15 


22 


30 


37 


45 


27.95 


68 


76 


83 


91 


2198 


05 


13 


21 


28 


36 


43 


28.00 


2166 


2174 


2181 


2189 


2196 


2204 


2212 


2219 


2227 


2234 


2242 


28.05 


65 


72 


80 


87 


95 


02 


10 


17 


25 


32 


40 


28.10 


63 


71 


78 


86 


93 


01 


08 


16 


23 


31 


38 


28.15 


61 


69 


77 


84 


92 


2199 


07 


14 


22 


29 


37 


28.20 


60 


67 


75 


82 


90 


97 


05 


12 


20 


27 


35 


28.25 


58 


66 


73 


81 


88 


96 


03 


11 


18 


26 


33 


28.30 


57 


64 


72 


79 


87 


94 


02 


' 09 


17 


24 


32 


28.35 


55 


62 


70 


77 


85 


92 


00 


07 


15 


22 


30 


28.40 


53 


61 


68 


76 


83 


91 


2198 


06 


13 


21 


28 


28.45 


52 


59 


67 


74 


82 


89 


97 


04 


12 


19 


27 


28.50 


2150 


2157 


2165 


2172 


2180 


2187 


2195 


2202 


2210 


2218 


2225 


28.55 


48 


56 


63 


71 


78 


86 


93 


01 


08 


16 


23 


28.60 


47 


54 


62 


69 


77 


84 


92 


2199 


07 


14 


22 


28.65 


45 


52 


60 


67 


75 


83 


90 


97 


05 


13 


20 


28.70 


43 


51 


58 


66 


73 


81 


88 


96 


03 


11 


18 


28.75 


42 


49 


57 


64 


72 


79 


87 


94 


02 


09 


17 


28.80 


40 


48 


55 


63 


70 


78 


85 


93 


00 


08 


15 


28.85 


38 


46 


53 


61 


68 


76 


83 


91 


2198 


06 


13 


28.90 


37 


44 


52 


59 


67 


74 


82 


89 


97 


04 


12 


28.95 


35 


43 


50 


58 


65 


73 


80 


88 


95 


03 


10 



DENSITY OF SEA WATER AND CORRECTIONS FOR THERMOMETERS 



33 



Table 1. For computing density, cr, of sea water for various values of salinity, S, 
and of temperature, t- -Continued 



Tem- 










Salinity, S, in 


%o 


































ture, t 


34.0 


34.1 


34.2 


34.3 


34.4 


34.5 


34.6 


34.7 


34.8 


34.9 


35.0 


29.00 


2133 


2141 


2148 


2156 


2163 


2171 


2178 


2186 


2193 


2201 


2208 


29.05 


32 


39 


47 


54 


62 


69 


77 


84 


92 


2199 


07 


29.10 


30 


38 


45 


53 


60 


68 


75 


83 


90 


98 


05 


29.15 


28 


36 


43 


51 


58 


66 


73 


81 


88 


96 


03 


29.20 


27 


34 


42 


49 


57 


64 


72 


79 


87 


94 


02 


29.25 


25 


32 


40 


47 


55 


63 


70 


77 


85 


93 


00 


29.30 


23 


31 


38 


46 


53 


61 


68 


76 


83 


91 


2198 


29.35 


22 


29 


37 


44 


52 


59 


67 


74 


82 


89 


97 


29.40 


20 


27 


35 


42 


50 


57 


65 


72 


80 


87 


95 


29.45 


18 


26 


33 


41 


48 


56 


63 


71 


78 


86 


93 


29.50 


2117 


2124 


2132 


2139 


2147 


2154 


2162 


2169 


2177 


2184 


2192 


29.55 


15 


22 


30 


37 


45 


52 


60 


67 


75 


82 


90 


29.60 


13 


21 


28 


36 


43 


51 


58 


66 


73 


81 


88 


29.65 


11 


19 


26 


34 


41 


49 


56 


64 


71 


79 


86 


29.70 


10 


17 


25 


32 


40 


47 


55 


62 


70 


77 


85 


29.75 


08 


16 


23 


31 


38 


46 


53 


61 


68 


76 


83 


29.80 


06 


14 


21 


29 


36 


44 


51 


59 


66 


74 


81 


29.85 


05 


12 


20 


27 


35 


42 


50 


57 


65 


72 


80 


29.90 


03 


11 


18 


26 


33 


41 


48 


56 


63 


71 


78 


29.95 


01 


09 


16 


24 


31 


39 


46 


54 


61 


69 


76 



30.00 



2100 



2107 



2115 



2122 



2130 



2137 



2145 



2152 



2160 



2167 



2175 



Tem- 


Salinity, S, in °/oo 


pera- 
ture, t 


35.0 


35.1 


35.2 


35.3 


35.4 


35.5 


35.6 


35.7 


35.8 


35.9 


36.0 



-2.00 


2820 


2828 


2837 


2845 


2853 


2861 


2869 


2877 


2885 


2893 


2902 


-1.95 


20 


28 


36 


45 


53 


61 


69 


77 


85 


93 


01 


-1.90 


20 


28 


36 


44 


52 


61 


69 


77 


85 


93 


01 


-1.85 


20 


28 


36 


44 


52 


60 


69 


77 


85 


93 


01 


-1.80 


20 


28 


36 


44 


52 


60 


68 


76 


85 


93 


01 


-1.75 


19 


28 


36 


44 


52 


60 


68 


76 


84 


93 


01 


-1.70 


19 


27 


36 


44 


52 


60 


68 


76 


84 


92 


00 


-1.65 


19 


27 


35 


44 


52 


60 


68 


76 


84 


92 


00 


-1.60 


19 


27 


35 


43 


51 


60 


68 


76 


84 


92 


00 


-1.55 


19 


27 


35 


43 


51 


59 


67 


76 


84 


92 


00 


-1.50 


2819 


2827 


2835 


2843 


2851 


2859 


2867 


2875 


2884 


2892 


2900 


-1.45 


19 


27 


35 


43 


51 


59 


67 


75 


83 


92 


00 


-1.40 


18 


26 


35 


43 


51 


59 


67 


75 


83 


91 


2899 


-1.35 


18 


26 


34 


43 


51 


59 


67 


75 


83 


91 


99 


-1.30 


18 


26 


34 


42 


50 


59 


67 


75 


83 


91 


99 


-1.25 


18 


26 


34 


42 


50 


58 


67 


75 


83 


91 


99 


-1.20 


18 


26 


34 


42 


50 


58 


66 


74 


83 


91 


99 


-1.15 


18 


26 


34 


42 


50 


58 


66 


74 


82 


90 


99 


-1.10 


17 


25 


34 


42 


50 


58 


66 


74 


82 


90 


98 


-1.05 


17 


25 


33 


42 


50 


58 


66 


74 


82 


90 


98 


-1.00 


2817 


2825 


2833 


2841 


2849 


2858 


2866 


2874 


2882 


2890 


2898 


-0.95 


17 


25 


33 


41 


49 


57 


65 


74 


82 


90 


98 


-0.90 


17 


25 


33 


41 


49 


57 


65 


73 


81 


89 


98 


-0.85 


16 


25 


33 


41 


49 


57 


65 


73 


81 


89 


97 


-0.80 


16 


24 


32 


40 


49 


57 


65 


73 


81 


89 


97 


-0.75 


16 


24 


32 


40 


48 


56 


64 


73 


81 


89 


97 


-0.70 


16 


24 


32 


40 


48 


56 


64 


72 


80 


88 


97 


-0.65 


15 


24 


32 


40 


48 


56 


64 


72 


80 


88 


96 


-0.60 


15 


23 


31 


40 


48 


56 


64 


72 


80 


88 


96 


-0.55 


15 


23 


31 


39 


47 


55 


64 


72 


80 


88 


96 


-0.50 


2815 


2823 


2831 


2839 


2847 


2855 


2863 


2871 


2879 


2888 


2896 


-0.45 


15 


23 


31 


39 


47 


55 


63 


71 


79 


87 


95 


-0.40 


14 


22 


31 


39 


47 


55 


63 


71 


79 


87 


95 


-0.35 


14 


22 


30 


38 


46 


54 


63 


71 


79 


87 


95 


-0.30 


14 


22 


30 


38 


46 


54 


62 


70 


7« 


87 


95 


-0.25 


14 


22 


30 


38 


46 


54 


62 


70 


78 


86 


94 


-0.20 


13 


22 


30 


38 


46 


54 


62 


70 


78 


86 


94 


-0.15 


13 


21 


29 


37 


46 


54 


62 


70 


78 


86 


94 


-0.10 


13 


21 


29 


37 


45 


53 


61 


69 


78 


86 


94 


-0.05 


13 


21 


29 


37 


45 


53 


61 


69 


77 


85 


93 



34 



OBSERVATIONS AND RESULTS IN PHYSICAL OCEANOGRAPHY 



Table 1. For computing density, a, of sea water for various values of salinity, S, 
and of temperature, t--Continued 



Tem- 










Salinity, S, in 


%o 










pera- 














































ture, t 


35.0 


35.1 


35.2 


25.3 


35.4 


35.5 


35.6 


35.7 


35.8 


35.9 


36.0 


o.°oo 


2813 


2821 


2829 


2837 


2845 


2853 


2861 


2869 


2877 


2885 


2893 


0.05 


12 


20 


28 


36 


44 


53 


61 


69 


77 


85 


93 


0.10 


12 


20 


28 


36 


44 


52 


60 


68 


76 


84 


93 


0.15 


12 


20 


28 


36 


44 


52 


60 


68 


76 


84 


92 


0.20 


11 


19 


27 


36 


44 


52 


60 


68 


76 


84 


92 


0.25 


11 


19 


27 


35 


43 


51 


59 


67 


76 


84 


92 


0.30 


11 


19 


27 


35 


43 


51 


59 


67 


75 


83 


91 


0.35 


10 


18 


27 


35 


43 


51 


59 


67 


75 


83 


91 


0.40 


10 


18 


26 


34 


42 


50 


58 


66 


75 


83 


91 


0.45 


10 


18 


26 


34 


42 


50 


58 


66 


74 


82 


90 


0.50 


2810 


2818 


2826 


2834 


2842 


2850 


2858 


2866 


2874 


2882 


2890 


0.55 


09 


17 


25 


33 


41 


50 


58 


66 


74 


82 


90 


0.60 


09 


17 


25 


33 


41 


49 


57 


65 


73 


81 


89 


0.65 


09 


17 


25 


33 


41 


49 


57 


65 


73 


81 


89 


0.70 


08 


16 


24 


32 


41 


49 


57 


65 


73 


81 


89 


0.75 


08 


16 


24 


32 


40 


48 


56 


64 


72 


80 


88 


0.80 


08 


16 


24 


32 


40 


48 


56 


64 


72 


80 


88 


0.85 


07 


15 


24 


32 


40 


48 


56 


64 


72 


80 


88 


0.90 


07 


15 


23 


31 


39 


47 


55 


63 


71 


80 


88 


0.95 


07 


15 


23 


31 


39 


47 


55 


63 


71 


79 


87 


1.00 


2807 


2815 


2823 


2831 


2839 


2847 


2855 


2863 


2871 


2879 


2887 


1.05 


06 


14 


22 


30 


38 


46 


54 


62 


70 


78 


86 


1.10 


06 


14 


22 


30 


38 


46 


54 


62 


70 


78 


86 


1.15 


05 


13 


22 


30 


38 


46 


54 


62 


70 


78 


86 


1.20 


05 


13 


21 


29 


37 


45 


53 


61 


69 


77 


85 


1.25 


05 


13 


21 


29 


37 


45 


53 


61 


69 


77 


85 


1.30 


04 


12 


20 


28 


36 


45 


53 


61 


69 


77 


85 


1.35 


04 


12 


20 


28 


36 


44 


52 


60 


68 


76 


84 


1.40 


04 


12 


20 


28 


36 


44 


52 


60 


68 


76 


84 


1.45 


03 


11 


19 


27 


35 


43 


51 


59 


67 


75 


83 


1.50 


2803 


2811 


2819 


2827 


2835 


2843 


2851 


2859 


2867 


2875 


2883 


1.55 


03 


11 


19 


27 


35 


43 


51 


59 


67 


75 


83 


1.60 


02 


10 


18 


26 


34 


42 


50 


58 


66 


74 


82 


1.65 


02 


10 


18 


26 


34 


42 


50 


58 


66 


74 


82 


1.70 


01 


09 


17 


26 


34 


42 


50 


58 


66 


74 


82 


1.75 


01 


09 


17 


25 


33 


41 


49 


57 


65 


73 


81 


1.80 


01 


09 


17 


25 


33 


41 


49 


57 


65 


73 


81 


1.85 


00 


08 


16 


24 


32 


40 


48 


56 


64 


72 


80 


1.90 


00 


08 


16 


24 


32 


40 


48 


56 


64 


72 


80 


1.95 


00 


08 


16 


24 


32 


40 


48 


56 


64 


72 


80 


2.00 


2799 


2807 


2815 


2823 


2831 


2839 


2847 


2855 


2863 


2871 


2879 


2.05 


99 


07 


15 


23 


31 


39 


47 


55 


63 


71 


79 


2.10 


98 


06 


14 


22 


30 


38 


46 


54 


62 


70 


78 


2.15 


98 


06 


14 


22 


30 


38 


46 


54 


62 


70 


78 


2.20 


98 


06 


14 


22 


30 


38 


46 


54 


62 


70 


78 


2.25 


97 


05 


13 


21 


29 


37 


45 


53 


61 


69 


77 


2.30 


97 


05 


13 


21 


29 


37 


45 


53 


61 


69 


77 


2.35 


96 


04 


12 


20 


28 


36 


44 


52 


60 


68 


76 


2.40 


96 


04 


12 


20 


28 


36 


44 


52 


60 


68 


76 


2.45 


95 


03 


11 


19 


27 


35 


43 


51 


59 


67 


75 


2.50 


2795 


2803 


2811 


2819 


2827 


2835 


2843 


2851 


2859 


2867 


2875 


2.55 


94 


02 


10 


18 


26 


34 


42 


50 


58 


66 


74 


2.60 


94 


02 


10 


18 


26 


34 


42 


50 


58 


66 


74 


2.65 


94 


02 


10 


18 


26 


34 


41 


49 


57 


65 


73 


2.70 


93 


01 


09 


17 


25 


33 


41 


49 


57 


65 


73 


2.75 


93 


01 


09 


17 


25 


33 


41 


49 


57 


65 


73 


2.80 


92 


00 


08 


16 


24 


32 


40 


48 


56 


64 


72 


2.85 


92 


00 


08 


16 


24 


32 


40 


48 


56 


64 


72 


2.90 


91 


2799 


07 


15 


23 


31 


39 


47 


55 


63 


71 


2.95 


91 


99 


07 


15 


23 


31 


39 


47 


55 


63 


71 


3.00 


2791 


2799 


2807 


2815 


2823 


2830 


2838 


2846 


2854 


2862 


2870 


3.05 


90 


98 


06 


14 


22 


30 


38 


46 


54 


62 


70 


3.10 


90 


98 


06 


14 


22 


29 


37 


45 


53 


61 


69 


3.15 


89 


97 


05 


13 


21 


29 


37 


45 


53 


61 


69 


3.20 


89 


97 


05 


13 


21 


28 


36 


44 


52 


60 


68 


3.25 


88 


96 


04 


12 


20 


28 


36 


44 


52 


60 


68 


3.30 


88 


96 


04 


12 


20 


27 


35 


43 


51 


59 


67 


3.35 


87 


95 


03 


11 


19 


27 


35 


43 


51 


59 


67 


3.40 


87 


95 


03 


11 


19 


26 


34 


42 


50 


58 


66 


3.45 


86 


94 


02 


10 


18 


26 


34 


42 


50 


58 


66 



DENSITY OF SEA WATER AND CORRECTIONS FOR THERMOMETERS 



35 



Table 1. For computing density, a, of sea water for various values of salinity, S, 
and of temperature, t--Continued 



Tem- 










Salinity, S, in 


%o 










pera- 
























ture, t 


35.0 


35.1 


35.2 


35.3 


35.4 


35.5 


35.6 


35.7 


35.8 


35.9 


36.0 


3.50 


2786 


2794 


2802 


2810 


2818 


2825 


2833 


2841 


2849 


2857 


2865 


3.55 


85 


93 


01 


09 


17 


25 


33 


41 


49 


57 


65 


3.60 


85 


93 


01 


09 


17 


24 


32 


40 


48 


56 


64 


3.65 


84 


92 


00 


08 


16 


24 


32 


40 


48 


56 


64 


3.70 


84 


92 


00 


08 


16 


23 


31 


39 


47 


55 


63 


3.75 


83 


91 


2799 


07 


15 


23 


31 


39 


47 


55 


63 


3.80 


83 


91 


99 


07 


15 


22 


30 


38 


46 


54 


62 


3.85 


82 


90 


98 


06 


14 


22 


30 


38 


46 


54 


62 


3.90 


82 


90 


98 


06 


14 


21 


29 


37 


45 


53 


61 


3.95 


81 


89 


97 


05 


13 


21 


29 


37 


45 


53 


61 


4.00 


2781 


2789 


2797 


2805 


2813 


2820 


2828 


2836 


2844 


2852 


2860 


4.05 


80 


88 


96 


04 


12 


20 


28 


36 


44 


52 


60 


4.10 


80 


88 


96 


03 


11 


19 


27 


35 


43 


51 


59 


4.15 


79 


87 


95 


03 


11 


19 


27 


35 


43 


50 


c 8 


4.20 


79 


86 


94 


02 


10 


18 


26 


34 


42 


50 


58 


4.25 


78 


86 


94 


02 


10 


18 


26 


33 


41 


49 


57 


4.30 


77 


85 


93 


01 


09 


17 


25 


33 


41 


49 


57 


4.35 


77 


85 


93 


01 


09 


16 


24 


32 


40 


48 


56 


4.40 


76 


84 


92 


00 


08 


16 


24 


32 


40 


48 


56 


4.45 


76 


84 


92 


00 


07 


15 


23 


31 


39 


47 


55 


4.50 


2775 


2783 


2791 


2799 


2807 


2815 


2823 


2831 


2839 


2847 


2855 


4.55 


75 


82 


90 


98 


06 


14 


22 


30 


38 


46 


54 


4.60 


74 


82 


90 


98 


06 


14 


22 


30 


38 


45 


53 


4.65 


73 


81 


89 


97 


05 


13 


21 


29 


37 


45 


53 


4.70 


73 


81 


89 


97 


05 


13 


21 


28 


36 


44 


52 


4.75 


72 


80 


88 


96 


04 


12 


20 


28 


36 


44 


52 


4.80 


72 


80 


88 


96 


04 


11 


19 


27 


35 


43 


51 


4.85 


71 


79 


87 


95 


03 


11 


19 


27 


35 


43 


50 


4.90 


71 


79 


87 


94 


02 


10 


18 


26 


34 


42 


50 


4.95 


70 


78 


86 


94 


02 


10 


18 


26 


33 


41 


49 


5.00 


2770 


2778 


2785 


2793 


2801 


2809 


2817 


2825 


2833 


2841 


2849 


5.05 


69 


77 


85 


93 


01 


09 


16 


24 


32 


40 


48 


5.10 


68 


76 


84 


92 


00 


08 


16 


24 


32 


40 


48 


5.15 


68 


76 


84 


91 


2799 


07 


15 


23 


31 


39 


47 


5.20 


67 


75 


83 


91 


99 


07 


15 


23 


30 


38 


46 


5.25 


66 


74 


82 


90 


98 


06 


14 


22 


30 


38 


46 


5.30 


66 


74 


82 


90 


98 


05 


13 


21 


29 


37 


45 


5.35 


65 


73 


81 


80 


97 


05 


13 


21 


29 


36 


44 


5.40 


65 


73 


81 


88 


96 


04 


12 


20 


28 


36 


44 


5.45 


64 


72 


80 


88 


96 


04 


12 


19 


27 


35 


43 


5.50 


2763 


2771 


2779 


2787 


2795 


2803 


2811 


2819 


2827 


2835 


2843 


5.55 


63 


71 


79 


87 


94 


02 


10 


18 


26 


34 


42 


5.60 


62 


70 


78 


86 


94 


02 


10 


18 


25 


33 


41 


5.65 


62 


69 


77 


85 


93 


01 


09 


17 


25 


33 


41 


5.70 


61 


69 


77 


85 


93 


01 


08 


16 


24 


32 


40 


5.75 


60 


68 


76 


84 


92 


00 


08 


16 


24 


31 


39 


5.80 


60 


68 


76 


83 


91 


2799 


07 


15 


23 


31 


39 


5.85 


59 


67 


75 


83 


91 


99 


07 


14 


22 


30 


38 


5.90 


59 


66 


74 


82 


90 


98 


06 


14 


22 


30 


38 


5.95 


58 


66 


74 


82 


89 


97 


05 


13 


21 


29 


37 


6.00 


2757 


2765 


2773 


2781 


2789 


2797 


2805 


2813 


2820 


2828 


2836 


6.05 


57 


64 


72 


80 


88 


96 


04 


12 


20 


28 


36 


6.10 


56 


64 


72 


80 


88 


95 


03 


11 


19 


27 


35 


6.15 


55 


63 


71 


79 


87 


95 


03 


10 


18 


26 


34 


6.20 


55 


63 


70 


78 


86 


94 


02 


10 


18 


26 


34 


6.25 


54 


62 


70 


78 


85 


93 


01 


09 


17 


25 


33 


6.30 


53 


61 


69 


77 


85 


93 


01 


08 


16 


24 


32 


6.35 


53 


60 


68 


76 


84 


92 


00 


08 


16 


24 


31 


6.40 


52 


60 


68 


76 


83 


91 


2799 


07 


15 


23 


31 


6.45 


51 


59 


67 


74 


83 


91 


99 


06 


14 


22 


30 


6.50 


2751 


2758 


2766 


2774 


2782 


2790 


2798 


2806 


2814 


2822 


2829 


6.55 


50 


58 


66 


74 


81 


89 


97 


05 


13 


21 


29 


6.60 


49 


57 


65 


73 


81 


89 


97 


04 


12 


20 


28 


6.65 


49 


56 


64 


72 


80 


88 


96 


04 


12 


19 


27 


6.70 


48 


56 


64 


72 


79 


87 


95 


03 


11 


19 


27 


6.75 


47 


55 


63 


71 


79 


87 


94 


02 


10 


18 


26 


6.80 


47 


54 


62 


70 


78 


86 


94 


10 


10 


17 


25 


6.85 


46 


54 


62 


69 


77 


85 


93 


01 


09 


17 


25 


6.90 


45 


53 


61 


69 


77 


85 


92 


00 


08 


16 


24 


6.95 


45 


52 


60 


68 


76 


84 


92 


00 


07 


15 


23 



36 



OBSERVATIONS AND RESULTS IN PHYSICAL OCEANOGRAPHY 



Table 1. For computing density, a, of sea water for various values of salinity, S, 
and of temperature, t--Continued 



Tem- 










Salinity, S, in 


%o 










pera- 
























ture, t 


35.0 


35.1 


35.2 


35.3 


35.4 


35.5 


35.6 


35.7 


35.8 


35.9 


36.0 


o 

7.00 


2744 


2752 


2760 


2768 


2775 


2783 


2791 


2799 


2807 


2815 


2823 


7.05 


43 


51 


59 


67 


75 


82 


90 


98 


06 


14 


22 


7.10 


42 


50 


58 


66 


74 


82 


90 


98 


05 


13 


21 


7.15 


42 


50 


57 


65 


73 


81 


89 


97 


05 


12 


20 


7.20 


41 


49 


57 


65 


72 


80 


88 


96 


04 


12 


20 


7.25 


40 


48 


56 


64 


72 


80 


87 


95 


03 


11 


19 


7.30 


40 


47 


55 


63 


71 


79 


87 


95 


02 


10 


18 


7.35 


39 


47 


54 


62 


70 


78 


86 


94 


02 


10 


17 


7.40 


38 


46 


54 


62 


70 


77 


85 


93 


01 


09 


17 


7.45 


37 


45 


53 


61 


69 


77 


84 


92 


00 


08 


16 


7.50 


2737 


2744 


2752 


2760 


2768 


2776 


2784 


2792 


2799 


2807 


2815 


7.55 


36 


44 


52 


59 


67 


75 


83 


91 


99 


07 


14 


7.60 


35 


43 


51 


59 


67 


74 


82 


90 


98 


06 


14 


7.65 


34 


42 


50 


58 


66 


74 


82 


89 


97 


05 


13 


7.70 


34 


42 


49 


57 


65 


73 


81 


89 


97 


04 


12 


7.75 


33 


41 


49 


56 


64 


72 


80 


88 


96 


04 


11 


7.80 


32 


40 


48 


56 


64 


72 


79 


87 


95 


03 


11 


7.85 


31 


39 


47 


55 


63 


71 


79 


86 


94 


02 


10 


7.90 


31 


39 


47 


54 


62 


70 


78 


86 


94 


01 


09 


7.95 


30 


38 


46 


54 


61 


69 


77 


85 


93 


01 


09 


8.00 


2729 


2737 


2745 


2753 


2761 


2769 


2776 


2784 


2792 


2800 


2808 


8.05 


29 


36 


44 


52 


60 


68 


76 


83 


91 


2799 


07 


8.10 


28 


36 


43 


51 


59 


67 


75 


83 


91 


98 


06 


8.15 


27 


35 


43 


50 


58 


66 


74 


82 


90 


98 


05 


8.20 


26 


34 


42 


50 


58 


65 


73 


81 


89 


97 


05 


8.25 


25 


33 


41 


49 


57 


65 


72 


80 


88 


96 


04 


8.30 


25 


33 


40 


48 


56 


64 


72 


80 


87 


95 


03 


8.35 


24 


32 


40 


47 


55 


63 


71 


79 


87 


94 


02 


8.40 


23 


31 


39 


47 


54 


62 


70 


78 


86 


94 


01 


8.45 


22 


30 


38 


46 


54 


61 


69 


77 


85 


93 


01 


8.50 


2722 


2729 


2737 


2745 


2753 


2761 


2769 


2776 


2784 


2792 


2800 


8.55 


21 


29 


36 


44 


52 


60 


68 


76 


83 


91 


2799 


8.60 


20 


28 


36 


43 


51 


59 


67 


75 


83 


90 


98 


8.65 


19 


27 


35 


43 


50 


58 


66 


74 


82 


90 


97 


8.70 


18 


26 


34 


42 


50 


58 


65 


73 


81 


89 


97 


8.75 


18 


25 


33 


41 


49 


57 


65 


72 


80 


88 


96 


8.80 


17 


25 


33 


40 


48 


56 


64 


72 


79 


87 


95 


8.85 


16 


24 


32 


39 


47 


55 


63 


71 


79 


86 


94 


8.90 


15 


23 


31 


39 


47 


54 


62 


70 


78 


86 


94 


8.95 


14 


* 22 


30 


38 


46 


54 


61 


69 


77 


85 


93 


9.00 


2714 


2722 


2729 


2737 


2745 


2753 


2761 


2768 


2776 


2784 


2792 


9.05 


13 


21 


29 


36 


44 


52 


60 


68 


75 


83 


91 


9.10 


12 


20 


28 


36 


43 


51 


59 


67 


75 


82 


90 


9.15 


11 


19 


27 


35 


42 


50 


58 


66 


74 


82 


89 


9.20 


10 


18 


26 


34 


42 


49 


57 


65 


73 


81 


89 


9.25 


10 


17 


25 


33 


41 


49 


56 


64 


72 


80 


88 


9.30 


09 


17 


24 


32 


40 


48 


56 


63 


71 


79 


87 


9.35 


08 


16 


24 


31 


39 


47 


55 


63 


70 


78 


86 


9.40 


07 


15 


23 


31 


38 


46 


54 


62 


70 


77 


85 


9.45 


06 


14 


22 


30 


37 


45 


53 


61 


69 


76 


84 


9.50 


2705 


2713 


2721 


2729 


2737 


2744 


2752 


2760 


2768 


2776 


2784 


9.55 


05 


12 


20 


28 


36 


44 


51 


59 


67 


75 


83 


9.60 


04 


12 


19 


27 


35 


43 


51 


58 


66 


74 


82 


9.65 


03 


11 


18 


26 


34 


42 


50 


58 


65 


73 


81 


9.70 


02 


10 


18 


25 


33 


41 


49 


57 


65 


72 


80 


9.75 


01 


09 


17 


25 


32 


40 


48 


56 


64 


72 


79 


9.80 


00 


08 


16 


24 


32 


39 


47 


55 


63 


71 


78 


9.85 


00 


07 


15 


23 


31 


39 


46 


54 


62 


70 


78 


9.90 


2699 


07 


14 


22 


30 


38 


46 


53 


61 


69 


77 


9.95 


98 


06 


13 


21 


29 


37 


45 


52 


60 


68 


76 


10.00 


2697 


2705 


2713 


2720 


2728 


2736 


2744 


2752 


2759 


2767 


2775 


10.05 


96 


04 


12 


20 


27 


35 


43 


51 


59 


66 


74 


10.10 


95 


03 


11 


19 


27 


34 


42 


50 


58 


65 


73 


10.15 


94 


02 


10 


18 


26 


33 


41 


49 


57 


65 


72 


10.20 


94 


01 


09 


17 


25 


33 


40 


48 


56 


64 


71 


10.25 


93 


00 


08 


16 


24 


32 


39 


47 


55 


63 


71 


10.31 


92 


DO 


07 


15 


23 


31 


39 


46 


54 


62 


70 


10.35 


91 


2699 


06 


14 


22 


30 


3S 


45 


53 


61 


69 


10.40 


90 


98 


06 


13 


21 


29 


37 


45 


52 


60 


68 


10.45 


89 


97 


05 


12 


20 


28 


36 


44 


51 


59 


67 



DENSITY OF SEA WATER AND CORRECTIONS FOR THERMOMETERS 



37 



Table 1. For computing density, a, of sea water for various values of salinity, S, 
and of temperature, t--Continued 



Tem- 
pera- 
ture, t 



Salinity, S, in °/oo 



35.0 



35.1 



35.2 



35.3 



35.4 



35.5 



35.6 



35.7 



35.8 



35.9 



36.0 



10.50 


2688 


2696 


2704 


2712 


2719 


2727 


2735 


2743 


2751 


2758 


2766 


10.55 


87 


95 


03 


11 


18 


26 


34 


42 


50 


57 


65 


10.60 


86 


94 


02 


10 


18 


25 


33 


41 


49 


57 


64 


10.65 


86 


93 


01 


09 


17 


24 


32 


40 


48 


56 


63 


10.70 


85 


93 


00 


08 


16 


24 


31 


39 


47 


55 


63 


10.75 


84 


92 


2699 


07 


15 


23 


30 


38 


46 


54 


62 


10.80 


83 


91 


99 


06 


14 


22 


30 


37 


45 


53 


61 


10.85 


82 


90 


98 


05 


13 


21 


29 


36 


44 


52 


60 


10.90 


81 


89 


97 


05 


12 


20 


28 


36 


43 


51 


59 


10.95 


80 


88 


96 


04 


11 


19 


27 


35 


42 


50 


58 


11.00 


2679 


2687 


2695 


2703 


2711 


2718 


2726 


2734 


2742 


2749 


2757 


11.05 


78 


86 


94 


02 


10 


17 


25 


33 


41 


48 


56 


11.10 


78 


85 


93 


01 


09 


16 


24 


32 


40 


48 


55 


11.15 


77 


84 


92 


00 


08 


15 


23 


31 


39 


47 


54 


11.20 


76 


83 


91 


2699 


07 


15 


22 


30 


38 


46 


53 


11.25 


75 


82 


90 


98 


06 


14 


21 


29 


37 


45 


52 


11.30 


74 


82 


89 


97 


05 


13 


20 


28 


36 


44 


52 


11.35 


73 


81 


88 


96 


04 


12 


19 


27 


35 


43 


51 


11.40 


72 


80 


87 


95 


03 


11 


19 


26 


34 


42 


50 


11.45 


71 


79 


86 


94 


02 


10 


18 


25 


33 


41 


49 


11.50 


2670 


2678 


2686 


2693 


2701 


2709 


2717 


2724 


2732 


2740 


2748 


11.55 


69 


77 


85 


92 


00 


08 


16 


23 


31 


39 


47 


11.60 


68 


76 


84 


91 


2699 


07 


15 


23 


30 


38 


46 


11.65 


67 


75 


83 


90 


98 


06 


14 


22 


29 


37 


45 


11.70 


66 


74 


82 


90 


97 


05 


13 


21 


28 


36 


44 


11.75 


65 


73 


81 


89 


96 


04 


12 


20 


27 


35 


43 


11.80 


64 


72 


80 


88 


96 


03 


11 


19 


27 


34 


42 


11.85 


63 


71 


79 


87 


95 


02 


10 


18 


26 


33 


41 


11.90 


63 


70 


78 


86 


94 


01 


09 


17 


25 


32 


40 


11.95 


62 


69 


77 


85 


93 


00 


08 


16 


24 


31 


39 


12.00 


2661 


2668 


2676 


2684 


2692 


2700 


2707 


2715 


2723 


2731 


2738 


12.05 


60 


67 


75 


83 


91 


99 


06 


14 


22 


30 


37 


12.10 


59 


67 


74 


82 


90 


98 


05 


13 


21 


29 


36 


12.15 


58 


66 


73 


81 


89 


97 


04 


12 


20 


28 


35 


12.20 


57 


65 


72 


80 


88 


96 


03 


11 


19 


27 


34 


12.25 


56 


64 


71 


79 


87 


95 


02 


10 


18 


26 


33 


12.30 


55 


63 


70 


78 


86 


94 


01 


09 


17 


25 


32 


12.35 


54 


62 


69 


77 


85 


93 


00 


08 


16 


24 


31 


12.40 


53 


61 


68 


76 


84 


92 


2699 


07 


15 


23 


30 


12.45 


52 


60 


67 


75 


83 


91 


98 


06 


14 


22 


29 


12.50 


2651 


2659 


2666 


2674 


2682 


2690 


2697 


2705 


2713 


2721 


2728 


12.55 


50 


58 


65 


73 


81 


89 


96 


04 


12 


20 


27 


12.60 


49 


57 


64 


72 


80 


88 


95 


03 


11 


19 


26 


12.65 


48 


56 


63 


71 


79 


87 


94 


02 


10 


18 


25 


12.70 


47 


55 


62 


70 


78 


86 


93 


01 


09 


17 


24 


12.75 


46 


54 


61 


69 


77 


85 


92 


00 


08 


16 


23 


12.80 


45 


53 


60 


68 


76 


84 


91 


2699 


07 


15 


22 


12.85 


44 


52 


59 


67 


75 


83 


90 


98 


06 


14 


21 


12.90 


43 


51 


59 


66 


74 


82 


89 


97 


05 


13 


20 


12.95 


42 


50 


58 


65 


73 


81 


88 


96 


04 


12 


19 


13.00 


2641 


2649 


2657 


2664 


2672 


2680 


2687 


2695 


2703 


2711 


2718 


13.05 


40 


48 


55 


63 


71 


79 


86 


94 


02 


10 


17 


13.10 


39 


47 


54 


62 


70 


78 


85 


93 


01 


09 


16 


13.15 


38 


46 


53 


61 


69 


77 


84 


92 


00 


08 


15 


13.20 


37 


45 


52 


60 


68 


76 


83 


91 


2699 


07 


14 


13.25 


36 


44 


51 


59 


67 


75 


82 


90 


98 


05 


13 


13.30 


35 


43 


50 


58 


66 


74 


81 


89 


97 


04 


12 


13.35 


34 


42 


49 


57 


65 


72 


80 


88 


96 


03 


11 


13.40 


33 


41 


48 


56 


64 


71 


79 


87 


95 


02 


10 


13.45 


32 


40 


47 


55 


63 


70 


78 


86 


94 


01 


09 


13.50 


2631 


2639 


2646 


2654 


2662 


2669 


2677 


2685 


2693 


2700 


2708 


13.55 


30 


37 


45 


53 


61 


68 


76 


84 


91 


2699 


07 


13.60 


29 


36 


44 


52 


60 


67 


75 


83 


91 


98 


06 


13.65 


28 


35 


43 


51 


59 


66 


74 


82 


89 


97 


05 


13.70 


27 


34 


42 


50 


58 


65 


73 


81 


88 


96 


04 


13.75 


26 


33 


41 


49 


56 


64 


72 


80 


87 


95 


03 


13.80 


25 


32 


40 


48 


55 


63 


71 


79 


86 


94 


02 


13.85 


24 


31 


39 


47 


54 


62 


70 


78 


85 


93 


01 


13.90 


23 


30 


38 


46 


53 


61 


69 


77 


84 


92 


00 


13.95 


21 


29 


37 


45 


52 


60 


68 


76 


83 


91 


2699 



38 



OBSERVATIONS AND RESULTS IN PHYSICAL OCEANOGRAPHY 



Table 1. For computing density, a, of sea water for various values of salinity, S, 
and of temperature, t- -Continued 



Tem- 










Salini 


ty, S, in o/oo 










pera- 
























ture, t 


35.0 


35.1 


35.2 


35.3 


35.4 


35.5 


35.6 


35.7 


35.8 


35.9 


36.0 


o 

14.00 


2620 


2628 


2636 


2644 


2651 


2659 


2667 


2674 


2682 


2690 


2698 


14.05 


19 


27 


35 


43 


50 


58 


66 


73 


81 


89 


97 


14.10 


18 


26 


34 


41 


49 


57 


65 


72 


80 


88 


95 


14.15 


17 


25 


33 


40 


48 


56 


63 


71 


79 


87 


94 


14.20 


16 


24 


32 


39 


47 


55 


62 


70 


78 


86 


93 


14.25 


15 


23 


30 


38 


46 


54 


61 


69 


77 


84 


92 


14.30 


14 


22 


29 


37 


45 


53 


60 


68 


76 


83 


91 


14.35 


13 


21 


28 


35 


44 


51 


59 


67 


75 


82 


90 


14.40 


12 


20 


27 


35 


43 


50 


58 


66 


74 


81 


89 


14.45 


11 


18 


26 


34 


42 


49 


57 


65 


72 


80 


88 


14.50 


26W) 


2617 


2625 


2633 


2641 


2648 


2656 


2664 


2671 


2679 


2687 


14.55 


09 


16 


24 


32 


39 


47 


55 


63 


70 


78 


86 


14.60 


08 


15 


23 


31 


38 


46 


54 


62 


69 


77 


85 


14.65 


06 


14 


22 


30 


37 


45 


53 


60 


68 


76 


83 


14.70 


05 


13 


21 


29 


36 


44 


" 52 


59 


67 


75 


82 


14.75 


04 


12 


20 


27 


35 


43 


51 


58 


66 


74 


81 


14.80 


03 


11 


19 


26 


34 


42 


49 


57 


65 


73 


80 


14.85 


02 


10 


18 


25 


33 


41 


48 


56 


64 


71 


79 


14.90 


01 


09 


17 


24 


32 


40 


47 


55 


63 


70 


78' 


14.95 


01 


08 


15 


23 


31 


39 


46 


54 


62 


69 


77 


15.00 


2599 


2607 


2614 


2622 


2630 


2637 


2645 


2653 


2661 


2668 


2676 


15.05 


98 


06 


13 


21 


29 


36 


44 


52 


59 


67 


75 


15.10 


97 


04 


12 


20 


28 


35 


43 


51 


58 


66 


74 


15.15 


96 


03 


11 


19 


26 


34 


42 


49 


57 


65 


73 


15.20 


95 


02 


10 


18 


25 


33 


41 


48 


56 


64 


71 


15.25 


93 


01 


09 


16 


24 


32 


39 


47 


55 


63 


70 


15.30 


92 


00 


08 


15 


23 


31 


38 


46 


54 


61 


89 


15.35 


91 


2599 


06 


14 


22 


30 


37 


45 


53 


60 


68 


15.40 


90 


98 


05 


13 


21 


28 


36 


44 


52 


59 


67 


15.45 


89 


97 


04 


12 


20 


27 


35 


43 


50 


58 


66 


15.50 


2588 


2595 


2603 


2611 


2619 


2626 


2634 


2642 


2649 


2657 


2665 


15.55 


87 


94 


02 


10 


17 


25 


33 


40 


48 


56 


64 


15.60 


86 


93 . 


01 


09 


16 


24 


32 


39 


47 


55 


62 


15.65 


84 


92 


00 


07 


15 


23 


30 


38 


46 


53 


61 


15.70 


83 


91 


2599 


06 


14 


22 


29 


37 


45 


52 


60 


15.75 


82 


90 


97 


05 


13 


21 


28 


36 


44 


51 


59 


15.80 


81 


89 


96 


04 


12 


19 


27 


35 


42 


50 


58 


15.85 


80 


88 


95 


03 


11 


18 


26 


34 


41 


49 


57 


15.90 


79 


86 


94 


02 


10 


17 


25 


33 


40 


48 


56 


15.95 


78 


85 


93 


01 


08 


16 


24 


31 


39 


47 


54 


16.00 


2577 


2584 


2592 


2600 


2607 


2615 


2623 


2630 


2638 


2646 


2653 


16.05 


75 


83 


91 


2598 


06 


14 


21 


29 


37 


45 


52 


16.10 


74 


82 


90 


97 


05 


13 


20 


28 


36 


43 


51 


16.15 


73 


81 


88 


96 


04 


11 


19 


27 


34 


42 


50 


16.20 


72 


80 


87 


95 


03 


10 


18 


26 


33 


41 


49 


16.25 


71 


78 


86 


94 


01 


09 


17 


24 


32 


40 


47 


16.30 


70 


77 


85 


93 


00 


08 


16 


23 


31 


39 


46 


16.35 


68 


76 


84 


91 


2599 


07 


14 


22 


30 


37 


45 


16.40 


67 


75 


83 


90 


98 


06 


13 


21 


29 


36 


44 


16.45 


66 


74 


81 


89 


97 


04 


12 


20 


27 


35 


43 


16.50 


2565 


2573 


2580 


2588 


2596 


2603 


2611 


2619 


2626 


2634 


2642 


16.55 


64 


71 


79 


87 


94 


02 


10 


17 


25 


33 


40 


16.60 


63 


70 


78 


86 


93 


01 


09 


16 


24 


32 


,39 


16.65 


61 


69 


77 


84 


92 


00 


07 


15 


23 


30 


38 


16.70 


60 


68 


76 


83 


91 


2599 


06 


14 


22 


29 


37 


16.75 


59 


67 


74 


82 


90 


97 


05 


13 


20 


28 


36 


16.80 


58 


66 


73 


81 


89 


96 


04 


12 


19 


27 


35 


16.85 


57 


64 


72 


80 


87 


95 


03 


10 


18 


26 


33 


16.90 


56 


63 


71 


79 


86 


94 


02 


09 


17 


25 


32 


16.95 


54 


62 


70 


77 


85 


93 


00 


08 


16 


23 


31 


17.00 


2553 


2561 


2569 


2576 


2584 


2592 


2599 


2607 


2614 


2622 


2630 


17.05 


52 


60 


67 


75 


83 


90 


98 


06 


13 


21 


29 


17.10 


51 


58 


66 


74 


81 


89 


97 


04 


12 


20 


27 


17.15 


50 


57 


65 


73 


80 


88 


96 


03 


11 


19 


26 


17.20 


48 


56 


64 


71 


79 


87 


94 


02 


10 


17 


25 


17.25 


47 


55 


62 


70 


78 


85 


93 


01 


08 


16 


24 


17.30 


46 


54 


61 


69 


77 


84 


92 


00 


07 


15 


23 


17.35 


45 


52 


60 


68 


75 


83 


91 


2598 


06 


14 


21 


17.40 


44 


51 


59 


67 


74 


82 


89 


97 


05 


12 


20 


17.45 


42 


50 


58 


65 


73 


81 


88 


96 


04 


11 


19 



DENSITY OF SEA WATER AND CORRECTIONS FOR THERMOMETERS 



39 



Table 1. For computing density, a, of sea water for various values of salinity, S, 
and of temperature, t--Continued 



Tem- 










Salinity, S, in 


%o 










pera- 
























ture, t 


35.0 


35.1 


35.2 


35.3 


35.4 


35.5 


35.6 


35.7 


35.8 


35.9 


36.0 


o 

17.50 


2541 


2549 


2556 


2564 


2572 


2579 


2587 


2595 


2602 


2610 


2618 


17.55 


40 


48 


55 


63 


71 


78 


86 


93 


01 


09 


16 


17.60 


39 


46 


54 


62 


69 


77 


85 


92 


00 


08 


15 


17.65 


37 


45 


53 


60 


68 


76 


83 


91 


2599 


06 


14 


17.70 


36 


44 


52 


59 


67 


75 


82 


90 


97 


05 


13 


17.75 


35 


43 


50 


58 


66 


73 


81 


89 


96 


04 


12 


17.80 


34 


42 


49 


57 


64 


72 


80 


87 


95 


03 


10 


17.85 


33 


40 


48 


56 


- 63 


71 


78 


86 


94 


01 


09 


17.90 


31 


39 


47 


54 


62 


70 


77 


85 


93 


00 


08 


17.95 


30 


38 


46 


53 


61 


69 


76 


84 


91 


2599 


07 


18.00 


2529 


2537 


2544 


2552 


2560 


2567 


2575 


2583 


2590 


2598 


2605 


18.05 


28 


35 


43 


51 


58 


66 


74 


81 


89 


97 


04 


18.10 


27 


34 


42 


49 


57 


65 


72 


80 


88 


95 


03 


18.15 


25 


33 


41 


48 


56 


64 


71 


79 


86 


94 


02 


18.20 


24 


32 


39 


47 


55 


62 


70 


78 


85 


93 


00 


18.25 


23 


30 


38 


46 


53 


61 


69 


76 


84 


92 


2599 


18.30 


22 


29 


37 


44 


52 


60 


67 


75 


83 


90 


98 


18.35 


20 


28 


36 


43 


51 


58 


66 


74 


81 


89 


97 


18.40 


19 


27 


34 


42 


50 


57 


65 


72 


80 


88 


95 


18.45 


18 


25 


33 


41 


48 


56 


64 


71 


79 


86 


94 


18.50 


2516 


2524 


2532 


2539 


2547 


2555 


2562 


2570 


2578 


2585 


2593 


18.55 


15 


23 


30 


38 


46 


53 


61 


69 


76 


84 


92 


18.60 


14 


22 


29 


37 


45 


52 


60 


67 


75 


83 


90 


18.65 


13 


20 


28 


36 


43 


51 


58 


66 


74 


81 


89 


18.70 


11 


19 


27 


34 


42 


50 


57 


65 


73 


80 


88 


18.75 


10 


18 


25 


33 


41 


48 


56 


64 


71 


79 


87 


18.80 


09 


17 


24 


32 


40 


47 


55 


62 


70 


78 


85 


18.85 


08 


15 


23 


31 


38 


46 


53 


61 


69 


76 


84 


18.90 


06 


14 


22 


29 


37 


45 


52 


60 


67 


75 


83 


18.95 


05 


13 


20 


28 


36 


43 


51 


59 


66 


74 


81 


19.00 


2504 


2512 


2519 


2527 


2534 


2542 


2550 


2557 


2565 


2573 


2580 


19.05 


03 


10 


18 


26 


33 


41 


48 


56 


64 


71 


79 


19.10 


01 


09 


17 


24 


32 


39 


47 


55 


62 


70 


78 


19.15 


00 


08 


15 


23 


31 


38 


46 


53 


61 


69 


76 


19.20 


2499 


06 


II 


22 


29 


37 


45 


52 


60 


67 


75 


19.25 


98 


05 


20 


28 


36 


43 


51 


58 


66 


74 


19.30 


96 


04 


11 


19 


27 


34 


42 


50 


57 


65 


72 


19.35 


95 


03 


10 


18 


25 


33 


41 


48 


56 


64 


71 


19.40 


94 


01 


09 


16 


24 


32 


39 


47 


55 


62 


70 


19.45 


92 


00 


08 


15 


23 


30 


38 


46 


53 


61 


68 


19.50 


2491 


2499 


2506 


2514 


2521 


2529 


2537 


2544 


2552 


2560 


2567 


19.55 


90 


97 


05 


13 


20 


28 


35 


43 


51 


58 


66 


19.60 


88 


96 


04 


11 


19 


27 


34 


42 


49 


57 


65 


19.65 


87 


95 


02 


10 


18 


25 


33 


40 


48 


56 


63 


19.70 


86 


93 


01 


09 


16 


24 


32 


39 


47 


54 


62 


19.75 


85 


92 


00 


07 


15 


23 


30 


38 


45 


53 


61 


19.80 


83 


91 ' 


2498 


06 


14 


21 


29 


37 


44 


52 


59 


19.85 


82 


90 


97 


05 


12 


20 


28 


35 


43 


51 


58 


19.90 


81 


88 


96 


03 


11 


19 


26 


34 


42 


49 


57 


19.95 


79 


87 


95 


02 


10 


17 


25 


33 


40 


48 


56 


20.00 


2478 


2486 


2493 


2501 


2509 


2516 


2524 


2531 


2539 


2547 


2554 


20.05 


77 


84 


92 


00 


07 


15 


22 


30 


38 


45 


53 


20.10 


75 


83 


91 


2498 


06 


13 


21 


29 


36 


44 


51 


20.15 


74 


82 


89 


97 


04 


12 


20 


27 


35 


43 


50 


20.20 


73 


80 


88 


96 


03 


11 


18 


26 


34 


41 


49 


20.25 


71 


79 


87 


94 


02 


09 


17 


25 


32 


40 


47 


20.30 


70 


78 


85 


93 


00 


08 


16 


23 


31 


38 


46 


20.35 


69 


76 


84 


92 


2499 


07 


14 


22 


30 


37 


45 


20.40 


67 


75 


83 


90 


98 


05 


13 


21 


28 


36 


43 


20.45 


66 


74 


81 


89 


96 


04 


12 


19 


27 


34 


42 


20.50 


2465 


2472 


2480 


2488 


2495 


2503 


2510 


2518 


2526 


2533 


2541 


20.55 


63 


71 


79 


86 


94 


01 


09 


17 


24 


32 


39 


20.60 


62 


70 


77 


85 


92 


00 


08 


15 


23 


30 


38 


20.65 


61 


68 


76 


83 


91 


2499 


06 


14 


21 


29 


37 


20.70 


59 


67 


75 


82 


90 


97 


05 


13 


20 


28 


35 


20.75 


58 


66 


73 


81 


88 


96 


04 


11 


19 


26 


34 


20.80 


57 


64 


72 


79 


87 


95 


02 


10 


17 


25 


33 


20.85 


55 


63 


71 


78 


86 


93 


01 


09 


16 


24 


31 


20.90 


54 


62 


69 


77 


84 


92 


00 


07 


15 


22 


30 


20.95 


53 


60 


68 


75 


83 


91 


2498 


06 


13 


21 


29 



40 



OBSERVATIONS AND RESULTS IN PHYSICAL OCEANOGRAPHY 



Table 1. For computing density, cr, of sea water for various values of salinity, S, 
and of temperature, t--Continued 



Tem- 










Salinity, S, in 


%0 










pera- 
























ture, t 


35.0 


35.1 


35.2 


35.3 


35.4 


35.5 


35.6 


35.7 


35.8 


35.9 


36.0 


21.00 


2451 


2459 


2467 


2474 


2482 


2489 


2497 


2504 


2512 


2520 


2527 


21.05 


50 


58 


65 


73 


80 


88 


96 


03 


11 


18 


26 


21.10 


49 


56 


64 


71 


79 


87 


94 


02 


09 


17 


25 


21.15 


47 


55 


62 


70 


78 


85 


93 


00 


08 


16 


23 


21.20 


46 


53 


61 


69 


76 


84 


91 


2499 


07 


14 


22 


21.25 


44 


52 


60 


67 


75 


82 


90 


98 


05 


13 


20 


21.30 


43 


51 


58 


66 


73 


81 


89 


96 


04 


11 


19 


21.35 


42 


49 


57 


64 


72 


80 


87 


95 


02 


10 


18 


21.40 


40 


48 


55 


63 


71 


78 


86 


93 


01 


09 


16 


21.45 


39 


46 


54 


62 


69 


77 


84 


92 


00 


07 


15 


21.50 


2438 


2445 


2453 


2460 


2468 


2475 


2483 


2491 


2498 


2506 


2513 


21.55 


36 


44 


51 


59 


67 


74 


82 


89 


97 


04 


12 


21.60 


35 


42 


50 


58 


65 


73 


80 


88 


95 


03 


11 


21.65 


33 


41 


49 


56 


64 


71 


79 


86 


94 


02 


09 


21.70 


32 


40 


47 


55 


62 


70 


78 


85 


93 


00 


08 


21.75 


31 


38 


46 


53 


61 


69 


76 


84 


91 


2499 


07 


21.80 


29 


37 


44 


52 


60 


67 


75 


82 


90 


98 


05 


21.85 


28 


35 


43 


51 


5"8 


66 


73 


81 


89 


96 


04 


21.90 


26 


34 


42 


49 


57 


64 


72 


80 


87 


95 


02 


21.95 


25 


33 


40 


48 


55 


63 


71 


78 


86 


93 


01 


22.00 


2424 


2431 


2439 


2446 


2454 


2462 


2469 


2477 


2484 


2492 


2500 


22.05 


22 


30 


37 


45 


53 


60 


68 


75 


83 


91 


2498 


22.10 


21 


28 


36 


44 


51 


59 


66 


74 


82 


89 


97 


22.15 


19 


27 


35 


42 


50 


57 


65 


73 


80 


88 


95 


22.20 


18 


26 


33 


41 


48 


56 


64 


71 


79 


86 


94 


22.25 


17 


24 


32 


39 


47 


55 


62 


70 


77 


85 


92 


22.30 


15 


23 


30 


38 


46 


53 


61 


68 


76 


83 


91 


22.35 


14 


21 


29 


37 


44 


52 


59 


67 


74 


82 


90 


22.40 


12 


20 


28 


35 


43 


50 


58 


65 


73 


81 


88 


22.45 


11 


19 


26 


34 


41 


49 


56 


64 


72 


79 


87 


22.50 


2410 


2417 


2425 


2432 


2440 


2447 


2455 


2463 


2470 


2478 


2485 


22.55 


08 


16 


23 


31 


38 


46 


54 


61 


69 


76 


84 


22.60 


07 


14 


22 


29 


37 


45 


52 


60 


67 


75 


82 


22.65 


05 


•13 


20 


28 


36 


43 


51 


58 


66 


73 


81 


22.70 


04 


11 


19 


27 


34 


42 


49 


57 


64 


72 


80 


22.75 


02 


10 


18 


25 


33 


40 


48 


56 


63 


71 


78 


22.80 


01 


09 


16 


24 


31 


39 


46 


54 


62 


69 


77 


22.85 


00 


07 


15 


22 


30 


37 


45 


53 


60 


68 


75 


22.90 


2398 


06 


13 


21 


28 


36 


44 


51 


59 


66 


74 


22.95 


97 


04 


12 


20 


27 


35 


42 


50 


57 


65 


73 


23.00 


2395 


2403 


2410 


2418 


2426 


2433 


2441 


2448 


2456 


2463 


2471 


23.05 


94 


01 


09 


17 


24 


32 


39 


47 


54 


62 


70 


23.10 


92 


00 


08 


15 


23 


30 


38 


45 


53 


61 


68 


23.15 


91 


2399 


06 


14 


21 


29 


36 


44 


52 


59 


67 


23.20 


90 


97 


05 


12 


20 


27 


35 


42 


50 


58 


.65 


23.25 


88 


96 


03 


11 


18 


26 


33 


41 


49 


56 


64 


23.30 


87 


94 


02 


09 


17 


24 


32 


40 


47 


55 


62 


23.35 


85 


93 


00 


08 


15 


23 


31 


38 


46 


53 


61 


23.40 


84 


91 


2399 


06 


14 


22 


29 


37 


44 


52 


59 


23.45 


82 


90 


97 


05 


12 


20 


28 


35 


43 


50 


58 


23.50 


2381 


2388 


2396 


2403 


2411 


2419 


2426 


2434 


2441 


2449 


2456 


23.55 


79 


87 


94 


02 


10 


17 


25 


32 


40 


47 


55 


23.60 


78 


85 


93 


01 


08 


16 


23 


31 


38 


46 


53 


23.65 


76 


84 


92 


2399 


07 


14 


22 


29 


37 


44 


52 


23.70 


75 


82 


90 


98 


05 


13 


20 


28 


35 


43 


51 


23.75 


73 


81 


89 


96 


04 


11 


19 


26 


34 


42 


49 


23.80 


72 


80 


87 


95 


02 


10 


17 


25 


32 


40 


48 


23.85 


71 


78 


86 


93 


01 


08 


16 


23 


31 


39 


46 


23.90 


69 


77 


84 


92 


2399 


07 


14 


22 


30 


37 


45 


23.95 


68 


75 


83 


90 


98 


05 


13 


21 


28 


36 


43 


24.00 


2366 


2374 


2381 


2389 


2396 


2404 


2412 


2419 


2427 


2434 


2442 


24.05 


65 


72 


80 


87 


95 


02 


10 


18 


25 


33 


40 


24.10 


63 


71 


78 


86 


93 


01 


09 


16 


24 


31 


39 


24.15 


62 


69 


77 


84 


92 


2399 


07 


15 


22 


30 


37 


24.20 


60 


68 


75 


83 


90 


" 98 


06 


13 


21 


28 


36 


24.25 


59 


66 


74 


81 


89 


96 


04 


12 


19 


27 


34 


24.30 


57 


65 


72 


80 


87 


95 


03 


10 


18 


25 


33 


24.35 


56 


63 


71 


78 


86 


93 


01 


09 


16 


24 


31 


24.40 


54 


62 


69 


77 


84 


92 


00 


07 


15 


22 


30 


24.45 


53 


60 


68 


75 


83 


90 


2398 


05 


13 


21 


28 



DENSITY OF SEA WATER AND CORRECTIONS FOR THERMOMETERS 



41 



Table 1. For computing density, <r, of sea water for various values of salinity, S, 
and of temperature, t--Continued 



Tem- 










Salini 


ty, S, in 


%o 










pera- 
























ture, t 


35.0 


35.1 


35.2 


35.3 


35.4 


35.5 


35.6 


35.7 


35.8 


35.9 


36.0 


24.50 


2351 


2359 


2366 


2374 


2381 


2389 


2396 


2404 


2412 


2419 


2427 


24.55 


50 


57 


65 


72 


80 


87 


95 


03 


10 


18 


25 


24.60 


48 


56 


63 


71 


78 


86 


93 


01 


09 


16 


24 


24.65 


47 


54 


62 


69 


77 


84 


92 


00 


07 


15 


22 


24.70 


45 


53 


60 


68 


75 


83 


90 


2398 


06 


13 


21 


24.75 


44 


51 


59 


66 


74 


81 


89 


97 


04 


12 


19 


24.80 


42 


50 


57 


65 


72 


80 


87 


95 


03 


10 


18 


24.85 


41 


48 


56 


63 


71 


78 


86 


94 


01 


09 


16 


24.90 


39 


47 


54 


62 


69 


77 


84 


92 


00 


07 


15 


24.95 


38 


44 


53 


60 


68 


75 


83 


91 


2398 


06 


13 


25.00 


2336 


2344 


2351 


2359 


2366 


2374 


2381 


2389 


2397 


2404 


2412 


25.05 


35 


42 


50 


57 


65 


72 


80 


87 


95 


03 


10 


25.10 


33 


41 


48 


56 


63 


71 


78 


86 


93 


01 


09 


25.15 


32 


39 


47 


54 


62 


69 


77 


84 


92 


2399 


07 


25.20 


30 


38 


45 


53 


60 


68 


75 


83 


90 


98 


05 


25.25 


28 


36 


44 


51 


59 


66 


74 


81 


89 


96 


04 


25.30 


27 


35 


42 


50 


57 


65 


72 


80 


87 


95 


02 


25.35 


25 


33 


41 


48 


56 


63 


71 


78 


86 


93 


01 


25.40 


24 


31 


39 


47 


54 


62 


69 


77 


84 


92 


2399 


25.45 


22 


30 


37 


45 


53 


60 


68 


75 


83 


90 


98 


25.50 


2321 


2328 


2336 


2343 


2351 


2359 


2366 


2374 


2381 


2389 


2396 


25.55 


19 


27 


34 


42 


49 


57 


65 


72 


80 


87 


95 


25.60 


18 


25 


33 


40 


48 


55 


63 


71 


78 


86 


93 


25.65 


16 


24 


31 


39 


46 


54 


61 


69 


77 


84 


92 


25.70 


15 


22 


30 


37 


45 


52 


60 


67 


75 


83 


90 


25.75 


13 


21 


28 


35 


43 


51 


58 


66 


73 


81 


88 


25.80 


12 


19 


27 


34 


42 


49 


57 


64 


72 


79 


87 


25.85 


10 


18 


25 


33 


40 


48 


55 


63 


70 


78 


85 


25.90 


09 


16 


24 


31 


39 


46 


54 


61 


69 


76 


84 


25.95 


07 


15 


22 


30 


37 


45 


52 


60 


67 


75 


82 


26.00 


2305 


2313 


2321 


2328 


2336 


2343 


2351 


2358 


2366 


2373 


2381 


26.05 


04 


11 


19 


26 


34 


42 


49 


57 


64 


72 


79 


26.10 


02 


10 


17 


25 


32 


40 


47 


55 


63 


70 


78 


26.15 


01 


08 


16 


23 


31 


38 


46 


53 


61 


68 


76 


26.20 


2299 


07 


14 


22 


29 


37 


44 


52 


59 


67 


74 


26.25 


98 


05 


13 


20 


28 


35 


43 


50 


58 


65 


73 


26.30 


96 


04 


11 


19 


26 


34 


41 


49 


56 


64 


71 


26.35 


94 


02 


09 


17 


25 


32 


40 


47 


55 


62 


70 


26.40 


93 


00 


08 


15 


23 


30 


38 


46 


53 


61 


68 


26.45 


91 


2299 


06 


14 


21 


29 


36 


44 


51 


59 


67 


26.50 


2290 


2297 


2305 


2312 


2320 


2327 


2335 


2342 


2350 


2357 


2365 


26.55 


88 


96 


03 


11 


18 


26 


33 


41 


48 


56 


63 


26.60 


87 


94 


02 


09 


17 


24 


32 


39 


47 


54 


62 


26.65 


85 


92 


00 


08 


15 


23 


30 


38 


45 


53 


60 


26.70 


83 


91 


2298 


06 


13 


21 


29 


36 


44 


51 


59 


26.75 


82 


89 


97 


04 


12 


19 


27 


34 


42 


50 


57 


26.80 


80 


88 


95 


03 


10 


18 


25 


33 


40 


48 


55 


26.85 


79 


86 


94 


01 


09 


16 


24 


31 


39 


46 


54 


26.90 


77 


85 


92 


00 


07 


15 


22 


30 


37 


45 


52 


26.95 


75 


83 


90 


2298 


06 


13 


21 


28 


36 


43 


51 


27.00 


2274 


2281 


2289 


2296 


2304 


2312 


2319 


2327 


2334 


2342 


2349 


27.05 


72 


80 


87 


95 


02 


10 


17 


25 


32 


40 


47 


27.10 


71 


78 


86 


93 


01 


08 


16 


23 


31 


38 


46 


27.15 


69 


77 


84 


92 


2299 


07 


14 


22 


29 


37 


44 


27.20 


67 


75 


82 


90 


98 


05 


13 


20 


28 


35 


42 


27.25 


66 


73 


81 


88 


96 


03 


11 


18 


26 


34 


41 


27.30 


64 


72 


79 


87 


94 


02 


09 


17 


24 


32 


39 


27.35 


63 


70 


78 


85 


93 


00 


08 


15 


23 


30 


38 


27.40 


61 


68 


76 


84 


91 


2299 


06 


14 


21 


29 


36 


27.45 


59 


67 


74 


82 


89 


97 


04 


12 


20 


27 


35 


27.50 


2258 


2265 


2273 


2280 


2288 


2295 


2303 


2310 


2318 


2325 


2333 


27.55 


56 


64 


71 


79 


86 


94 


01 


09 


16 


24 


31 


27.60 


54 


62 


70 


77 


85 


92 


00 


07 


15 


22 


30 


27.65 


53 


60 


68 


75 


83 


90 


2298 


06 


13 


21 


28 


27.70 


51 


59 


66 


74 


81 


89 


96 


04 


11 


19 


26 


27.75 


50 


57 


65 


72 


80 


87 


95 


02 


10 


17 


25 


27.80 


48 


56 


63 


71 


78 


86 


93 


01 


08 


16 


23 


27.85 


46 


54 


62 


69 


76 


84 


91 


2299 


07 


14 


22 


27.90 


45 


52 


60 


67 


75 


82 


90 


97 


05 


12 


20 


27.95 


43 


51 


58 


66 


73 


81 


88 


96 


03 


11 


18 



42 



OBSERVATIONS AND RESULTS IN PHYSICAL OCEANOGRAPHY 



Table 1. For computing density, a, of sea water for various values of salinity, S, 
and of temperature, t- -Concluded 



Tem- 










Salinity, S, in 


%o 










pera- 
























ture, t 


35.0 


35.1 


35.2 


35.3 


35.4 


35.5 


35.6 


35.7 


35.8 


35.9 


36.0 


28.00 


2242 


2249 


2257 


2264 


2272 


2279 


2287 


2294 


2302 


2309 


2317 


28.05 


40 


47 


55 


62 


70 


77 


85 


93 


00 


08 


15 


28.10 


38 


46 


53 


61 


68 


76 


83 


91 


2298 


06 


13 


28.15 


37 


44 


52 


59 


67 


74 


82 


89 


97 


04 


12 


28.20 


35 


42 


50 


57 


65 


73 


80 


88 


95 


03 


10 


28.25 


33 


41 


48 


56 


63 


71 


78 


86 


93 


01 


08 


28.30 


32 


39 


47 


54 


62 


69 


77 


84 


92 


2299 


07 


28.35 


30 


38 


45 


53 


60 


68 


75 


83 


90 


98 


05 


28.40 


28 


36 


43 


51 


58 


66 


73 


81 


88 


96 


03 


28.45 


27 


34 


42 


49 


57 


64 


72 


79 


87 


94 


02 


28.50 


2225 


2233 


2240 


2248 


2255 


2263 


2270 


2278 


2285 


2293 


2300 


28.55 


23 


31 


38 


46 


53 


61 


68 


76 


83 


91 


2298 


28.60 


22 


29 


37 


44 


52 


59 


67 


74 


82 


89 


97 


28.65 


20 


28 


35 


43 


50 


58 


65 


73 


80 


88 


95 


28.70 


18 


26 


33 


41 


48 


56 


63 


71 


78 


86 


93 


28.75 


17 


24 


32 


39 


47 


54 


62 


69 


77 


84 


92 


28.80 


15 


23 


30 


38 


45 


53 


60 


68 


75 


83 


90 


28.85 


13 


21 


28 


36 


43 


51 


58 


66 


73 


81 


88 


28.90 


12 


19 


27 


34 


42 


49 


57 


64 


72 


79 


87 


28.95 


10 


18 


25 


33 


40 


48 


55 


63 


70 


78 


85 


29.00 


2208 


2216 


2223 


2231 


2238 


2246 


2253 


2261 


2269 


2276 


2284 


29.05 


07 


14 


22 


29 


37 


44 


52 


59 


67 


74 


82 


29.10 


05 


13 


20 


28 


35 


43 


50 


58 


65 


73 


80 


29.15 


03 


11 


18 


26 


33 


41 


48 


56 


63 


71 


78 


29.20 


02 


09 


17 


24 


32 


39 


47 


54 


62 


69 


77 


29.25 


00 


08 


15 


23 


30 


38 


45 


53 


60 


68 


75 


29.30 


2198 


06 


13 


21 


28 


36 


43 


51 


58 


66 


73 


29.35 


97 


04 


12 


19 


27 


34 


42 


49 


57 


64 


72 


29.40 


95 


02 


10 


17 


25 


32 


40 


47 


55 


62 


70 


29.45 


93 


01 


08 


16 


23 


31 


38 


46 


53 


61 


68 


29.50 


2192 


2199 


2207 


2214 


2222 


2229 


2237 


2244 


2252 


2259 


2267 


29.55 


90 


97 


05 


12 


20 


27 


35 


42 


50 


57 


65 


29.60 


88 


96 


03 


11 


18 


26 


33 


41 


48 


56 


63 


29.65 


86 


94 


01 


09 


16 


24 


31 


39 


46 


54 


61 


29.70 


85 


92 


2200 


07 


15 


22 


30 


37 


45 


52 


60 


29.75 


83 


91 


2198 


06 


13 


21 


28 


36 


43 


51 


58 


29.80 


81 


89 


96 


04 


11 


19 


26 


34 


41 


49 


56 


29.85 


80 


87 


95 


02 


10 


17 


25 


32 


40 


47 


55 


29.90 


78 


86 


93 


00 


08 


15 


23 


30 


38 


45 


53 


29.95 


76 


84 


91 


2199 


06 


14 


21 


29 


36 


44 


51 


30.00 


2175 


2182 


2190 


2197 


2205 


2212 


2220 


2227 


2235 


2242 


2250 



DENSITY OF SEA WATER AND CORRECTIONS FOR THERMOMETERS 



43 



Table 2. Corrections for depth and temperature and 

(Tabular values are in. 



Depth 
dy- 












Temperature, t, 


in degrees centigrade 






namic 
meters 


-2 


-1 





1 


2 


3 


4 


5 


6 


7 


8 


9 


10 












































5 


2 


2 


2 


2 


2 


2 


2 


2 


2 


2 


2 


2 


2 


25 


12 


12 


12 


12 


12 


12 


12 


12 


12 


12 


12 


12 


12 


50 


25 


25 


25 


25 


25 


25 


25 


25 


24 


24 


24 


24 


24 


75 


38 


38 


37 


36 


36 


36 


36 


36 


35 


35 


35 


35 


35 


100 


50 


49 


49 


49 


48 


48 


48 


48 


47 


47 


47 


47 


47 


150 


75 


74 


74 


73 


73 


73 


72 


72 


71 


71 


71 


71 


70 


200 


99 


99 


98 


97 


97 


96 


96 


95 


95 


94 


94 


94 


93 


250 


124 


124 


123 


122 


121 


121 


120 


120 


119 


118 


118 


117 


117 


300 


149 


148 


147 


146 


145 


144 


144 


143 


142 


142 


141 


140 


140 


400 


198 


197 


196 


195 


194 


193 


192 


191 


190 


189 


188 


187 


187 


500 


248 


246 


245 


244 


242 


241 


240 


238 


237 


236 


235 


234 


233 


700 


346 


344 


342 


340 


338 


336 


334 


333 


331 


330 


328 


327 


326 


1000 


493 


490 


487 


484 


482 


479 


476 


474 


472 


470 


468 


466 


464 


1500 


736 


732 


728 


724 


719 


716 


712 


709 


705 


702 


699 


696 


694 


2000 


977 


971 


965 


960 


954 


949 


945 


940 


936 


931 


927 


924 


920 


2500 


1214 


1207 


1200 


1193 


1187 


1181 


1175 


1169 


1164 


1159 


1154 


1149 


1145 


3000 


1451 


1442 


1434 


1426 


1419 


1411 


1404 


1398 


1391 


1385 


1379 


1374 


1369 


3500 


1684 


1674 


1665 


1656 


1647 


1639 


1631 


1623 


1616 


1609 


1602 


1596 


1590 


4000 


1915 


1903 


1893 


1883 


1873 


1864 


1855 


1846 


1838 


1830 


1823 


1816 


1809 


4500 


2144 


2132 


2120 


2109 


2098 


2088 


2078 


2068 












5000 


2371 


2358 


2345 


2333 


2321 


2309 


2299 


2288 












5500 


2596 


2581 


2567 


2553 


2541 


















6000 


2819 


2803 


2788 


2773 


2760 



















for depth and salinity to obtain density of sea water 
units of fifth decimal) 





Salinity, S, in o/oo 


Depth 
dy- 


15 


20 


25 


30 


30 


31 


32 


33 


34 


35 


36 


37 


38 


39 


40 


namic 
meters 





2 

11 

23 

35 

46 

69 

92 

115 

137 

183 

229 

320 

456 

682 

905 

1126 

1347 

1565 

1780 





2 

11 

23 

34 

45 

68 

90 

113 

136 

181 

226 

316 





2 

11 

23 

34 

45 

67 

89 

111 

134 

179 




2 
11 
23 
34 
45 
66 
87 













1 

1 

2 

2 

2 

3 

4 

6 

8 

12 

16 

20 

23 

27 

30 

34 

37 













1 

1 

1 

2 

2 

3 

3 

5 

7 

10 

13 

16 

19 

22 

24 

27 

30 















1 

1 

1 

1 

2 

3 

3 

5 

8 

10 

12 

14 

16 

18 

20 

22 











1 
1 
1 
1 

2 

2 

3 

4 

6 

8 

9 

11 

12 

14 

15 

16 

17 














1 
1 
1 

2 
2 
3 

4 
5 
5 
6 

7 
8 
8 
9 









































-1 
-1 
-1 

-2 
-2 
-3 

-4 
-5 
-5 
-6 
-7 
-8 
-8 
-9 











- 1 

- 1 

- 1 

- 1 

- 2 

- 2 

- 3 

- 4 

- 6 

- 8 

- 9 
-11 
-12 
-14 
-15 
■16 
•17 










- 1 

- 1 

- 1 

- 1 

- 2 

- 3 

- 3 

- 5 

- 8 
-10 
-12 
-14 
-16 
-18 
-20 
-22 









- 1 

- 1 

- 1 

- 1 

- 2 

- 3 

- 3 

- 5 

- 7 
-10 
-13 
-16 
-19 
-22 
-24 
-27 
-30 









- 1 

- 1 

- 2 

- 2 

- 2 

- 3 

- 4 

- 6 

- 8 
-12 
-16 
-20 
-23 
-27 
-30 
-34 
-37 





5 

25 

50 

75 

100 

150 

200 

250 

300 

400 

500 

700 

1000 

1500 

2000 

2500 

3000 

3500 

4000 

4500 

5000 

5500 

6000 



44 



OBSERVATIONS AND RESULTS IN PHYSICAL OCEANOGRAPHY 



Table 3. Corrections for protected deep-sea reversing thermometer because of differences between 

observed reading T', and reading, t, of auxiliary attached thermometer; total correction At is 

sum of tabular value (negative for negative values of T'-t) and index correction I* 



Obs'd. 
temp. 


(T'+ Vo) in degrees centigrade 


diff. 
(T'-t) 


91 


92 


93 


94 


95 


96 


97 


98 


99 


100 


1 


0.015 


0.015 


0.015 


0.016 


0.016 


0.016 


0.016 


0.016 


0.016 


0.017 


2 


0.030 


0.031 


0.031 


0.031 


0.032 


0.032 


0.032 


0.033 


0.033 


0.033 


3 


0.045 


0.046 


0.046 


0.047 


0.047 


0.048 


0.048 


0.049 


0.049 


0.050 


4 


0.061 


0.061 


0.062 


0.063 


0.063 


0.064 


0.065 


0.065 


0.066 


0.067 


5 


0.076 


0.077 


0.077 


0.078 


0.079 


0.080 


0.081 


0.082 


0.082 


0.083 


6 


0.091 


0.092 


0.093 


0.094 


0.095 


0.096 


0.097 


0.098 


0.099 


0.100 


7 


0.106 


0.107 


0.108 


0.110 


0.111 


0.112 


0.113 


0.114 


0.115 


0.117 


8 


0.121 


0.122 


0.124 


0.125 


0.127 


0.128 


0.129 


0.131 


0.132 


0.133 


9 


0.136 


0.138 


0.139 


0.141 


0.142 


0.144 


0.145 


0.147 


0.148 


0.150 


10 


0.151 


0.153 


0.155 


0.156 


0.158 


0.160 


0.162 


0.163 


0.165 


0.167 


11 


0.167 


0.168 


0.170 


0.172 


0.174 


0.176 


0.178 


0.180 


0.181 


0.183 


12 


0.182 


0.184 


0.186 


0.188 


0.190 


0.192 


0.194 


0.196 


0.198 


0.200 


13 


0.197 


0.199 


0.201 


0.203 


0.206 


0.208 


0.210 


0.212 


0.214 


0.217 


14 


0.212 


0.214 


0.217 


0.219 


0.221 


0.224 


0.226 


0.229 


0.231 


0.233 


15 


0.227 


0.230 


0.232 


0.235 


0.237 


0.240 


0.242 


0.245 


0.247 


0.250 


16 


0.242 


0.245 


0.247 


0.250 


0.253 


0.256 


0.258 


0.261 


0.264 


0.267 


17 


0.257 


0.260 


0.263 


0.266 


0.269 


0.272 


0.275 


0.277 


0.280 


0.283 


18 


0.273 


0.276 


0.279 


0.282 


0.285 


0.288 


0.291 


0.294 


0.297 


0.300 


19 


0.288 


0.291 


0.294 


0.297 


0.301 


0.304 


0.307 


0.310 


0.315 


0.317 


20 


0.303 


0.306 


0.310 


0.313 


0.316 


0.320 


0.323 


0.326 


0.330 


0.333 


21 


0.318 


0.321 


0.325 


0.329 


0.332 


0.336 


0.33y 


0.343 


0.346 


0.350 


22 


0.333 


0.337 


0.340 


0.344 


0.348 


0.352 


0.355 


0.359 


0.363 


0.367 


23 


0.348 


0.352 


0.356 


0.360 


0.364 


0.368 


0.372 


0.375 


0.379 


0.383 


24 


0.363 


0.367 


0.371 


0.376 


0.380 


0.384 


0.388 


0.392 


0.396 


0.400 


25 


0.379 


0.383 


0.387 


0.391 


0.395 


0.400 


0.404 


0.408 


0.412 


0.417 


26 


0.394 


0.398 


0.402 


0.407 


0.411 


0.416 


0.420 


0.424 


0.429 


0.433 


27 


0.409 


0.413 


0.418 


0.422 


0.427 


0.432 


0.436 


0.441 


0.445 


0.450 


28 


0.424 


0.429 


0.433 


0.438 


0.443 


0.448 


0.452 


0.457 


0.462 


0.467 


29 


0.439 


0.444 


0.449 


0.454 


0.459 


0.464 


0.468 


0.473 


0.478 


0.483 


30 


0.454 


0.459 


0.464 


0.459 


0.474 


0.480 


0.485 


0.490 


0.495 


0.500 


31 


0.469 


0.475 


0.480 


0.485 


0.490 


0.496 


0.501 


0.506 


0.511 


0.517 


32 


0.485 


0.490 


0.495 


0.501 


0.506 


0.512 


0.517 


0.522 


0.528 


0.533 


33 


0.500 


0.505 


0.511 


0.516 


0.522 


0.528 


0.533 


0.53y 


0.544 


0.550 


34 


0.515 


0.521 


0.526 


0.532 


0.538 


0.543 


0.549 


0.555 


0.561 


0.567 


35 


0.530 


0.536 


0.542 


0.548 


0.554 


0.559 


0.565 


0.571 


0.577 


0.583 


36 


0.545 


0.551 


0.557 


0.563 


0.569 


0.575 


0.582 


0.588 


0.594 


0.600 


37 


0.560 


0.566 


0.573 


0.579 


0.585 


0.591 


0.598 


0.604 


0.610 


0.616 


38 


0.575 


0.582 


0.588 


0.595 


0.601 


0.607 


0.614 


0.620 


0.627 


0.633 


39 


0.590 


0.597 


0.604 


0.610 


0.617 


0.623 


0.630 


0.637 


0.643 


0.650 


40 


0.606 


0.612 


0.619 


0.626 


0.633 


0.639 


0.646 


0.653 


0.660 


0.666 


41 


0.621 


0.628 


0.635 


0.641 


0.648 


0.655 


0.662 


0.669 


0.676 


0.683 


42 


0.636 


0.643 


0.650 


0.657 


0.664 


0.671 


0.678 


0.686 


0.693 


0.700 


43 


0.651 


0.658 


0.666 


0.673 


0.680 


0.687 


0.695 


0.702 


0.709 


0.716 


44 


0.666 


0.674 


0.681 


0.688 


0.696 


0.703 


0.711 


0.718 


0.726 


0.733 


45 


0.681 


0.689 


0.696 


0.704 


0.712 


0.719 


0.727 


0.735 


0.742 


0.750 


46 


0.696 


0.704 


0.712 


0.720 


0.728 


0.735 


0.743 


0.751 


0.759 


0.766 


47 


0.712 


0.720 


0.727 


0.735 


0.743 


0.751 


0.759 


0.767 


0.775 


0.783 


48 


0.727 


0.735 


0.743 


0.751 


0.759 


0.767 


0.775 


0.784 


0.792 


0.800 


49 


0.742 


0.750 


0.758 


0.767 


0.775 


0.783 


0.792 


0.800 


0.808 


0.816 


50 


0.757 


0.765 


0.774 


0.782 


0.791 


0.799 


0.808 


0.816 


0.825 


0.833 


51 


0.772 


0.781 


0.789 


0.798 


0.807 


0.815 


0.824 


0.832 


0.841 


0.850 


52 


0.787 


0.796 


0.805 


0.814 


0.822 


0.831 


0.840 


0.849 


0.858 


0.866 


53 


0.802 


0.811 


0.820 


0.829 


0.838 


0.847 


0.856 


0.865 


0.874 


0.883 


54 


0.818 


0.827 


0.836 


0.845 


0.854 


0.863 


0.872 


0.881 


0.891 


0.900 


55 


0.833 


0.842 


0.851 


0.861 


0.870 


0.879 


0.888 


0.898 


0.907 


0.916 


56 


0.848 


0.857 


0.867 


0.876 


0.886 


0.895 


0.905 


0.914 


0.924 


0.933 


57 


0.863 


0.873 


0.882 


0.8y2 


0.902 


0.911 


0.921 


0.930 


0.940 


0.950 


58 


0.878 


0.888 


0.898 


0.907 


0.917 


0.927 


0.937 


0.y47 


0.957 


0.966 


59 


0.893 


0.903 


0.913 


0.923 


0.933 


0.y43 


0.953 


0.963 


0.973 


0.983 


60 


0.908 


0.919 


0.929 


0.939 


0.949 


0.y59 


0.y6y 


0.979 


0.990 


1.000 



* Strictly speaking, At = tabular value + I + 0.000164 (T'+ v Q ) I, but the term 0.00164 (T'+ v ) I 
may be neglected for well-made thermometers for which I does not exceed 0. 1. 





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JNPROTECTED DEEP-SEA REVERSING THERMOMETER 
FOR JENA GLASS 59 1 " FOR WHICH K=6I00 






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45 



DEPTH TO BOTTOM AT CARNEGIE STATIONS 



At a number of stations from station 7 to station 49 
wire depths were obtained by the 4 -mm wire. In all 
cases a water bottle provided with an unprotected and a 
protected thermometer was attached to the end of the 
wire and the depth was computed from the indications of 
the thermometers. The accuracy of this method has 
been discussed previously. No independent determina- 
tions of depth by means of the 4-mm wire were made and 
it is, therefore, unnecessary to enter on a discussion of 
the relation between wire length, wire angle, and depth 
at these stations. 

At the greater number of the stations from 40 to 162 
the depth was determined by means of sounding with 
piano wire. The wire angle was in many instances very 
great and it is, therefore, necessary to examine the re- 
lation between wire length, wire angle, and depth in 
these cases. In a number of cases a reversing frame, 
carrying two thermometers, one unprotected and one 
protected, was attached to the end of the wire. This 
frame was released by a propeller and according to ex- 
periments it had to be hauled up a distance of 25 meters 
before it vas reversed. From the indications of the two 
thermometers the depth at which the frame was re- 



versed can be computed with an accuracy of about +0.5 
per cent. Adding to this depth the distance of the frame 
from the lead at the end of the wire and the distance of 
25 meters which the frame had to be hauled up before 
reversal, the depth at the station is obtained with the 
same accuracy. Omitting the observations at eight sta- 
tions at which the frame evidently had reversed at a 
wrong level, thirty-four stations remain from which cor- 
responding values of depth, wire length and wire angle 
are available. The data from these stations have been 
compiled in table 1 in which the cosine of the wire angle 
and the ratio between the observed depth and the wire 
length also are entered, the latter under the headline 
"depth factor." It is seen that the depth factor is usual- 
ly smaller than the cosine of the wire angle at the sur- 
face, which means that the wire angle decreased when 
approaching the bottom. 

In figure 1 the depth factor has been plotted against 
the wire angle and the single values are grouped around 
a smooth curve. The scattering of the values is small, 
considering that the depth factor for any given wire angle 
depends on the curvature of the wire which again is con- 
trolled by the change of current with depth, and by the 



Table 1. Comparison between wire length, wire angle, and thermometer depth at stations where 

sounding with piano wire was undertaken 



Sta- 
tion 
no. 



Wire 
length, 
meters 



Wire 

angle, 

degrees 



Cosine 

of 

wire 

angle 



Ther- 
mom- 
eter 
depth, 
meters 



Depth 
factor 



Adopt- 
ed 
depth 
factor 



Wire 
depth, 
meters 



Thermometer 

depth minus 

wire depth, 

meters 



52 


2873 


18 


0.951 


2851 


0.992 


0.978 


2810 


41 


64 


3902 


17 


0.956 


3879 


0.994 


0.979 


3820 


59 


65 


3698 


25 


0.906 


3626 


0.981 


0.968 


3580 


46 


67 


1100 


12 


0.978 


1089 


0.990 


0.986 


1085 


4 


82 


3937 


47 


0.682 


3631 


0.922 


0.928 


3654 


-23 


83 


4100 


25 


0.906 


3982 


0.971 


0.968 


3969 


13 


84 


4187 


18 


0.951 


4121 


0.984 


0.978 


4095 


26 


85 


3814 


5 


0.996 


3770 


0.988 


0.994 


3791 


-21 


86 


2175 


19 


0.946 


2132 


0.980 


0.977 


2125 


7 


110 


3067 


10 


0.985 


3036 


0.990 


0.988 


3030 


6 


117 


5410 


22 


0.927 


5296 


0.979 


0.972 


5259 


37 


127 


4310 


41 


0.755 


4018 


0.932 


0.940 


4051 


-33 


127 


4273 


50 


0.643 


4034 


0.944 


0.921 


3935 


99 


128 


4105 


51 


0.629 


3785 


0.922 


0.919 


3772 


13 


128 


4194 


52 


0.616 


3826 


0.912 


0.916 


3842 


-16 


131 


4586 


30 


0.866 


4418 


0.963 


0.960 


4403 


15 


132 


4456 


35 


0.819 


4251 


0.954 


0.951 


4238 


13 


133 


4652 


33 


0.839 


4426 


0.951 


0.954 


4438 


-12 


134 


4676 


12 


0.978 


4528 


0.968 


0.986 


4611 


-83 


135 


4882 


10 


0.985 


4695 


0.962 


0.988 


4823 


-128 


137 


5506 


45 


0.707 


5208 


0.946 


0.932 


5132 


75 


138 


6057 


65 


0.423 


5382 


0.889 


0.884 


5354 


28 


139 


5429 


35 


0.819 


5030 


0.927 


0.951 


5163 


-133 


140 


5222 


55 


0.574 


4762 


0.912 


0.910 


4752 


10 


141 


6018 


45 


0.707 


5667 


0.942 


0.932 


5609 


58 


142 


6051 


32 


0.848 


5787 


0.956 


0.956 


5787 





146 


5328 


58 


0.530 


4756 


0.893 


0.902 


4806 


-50 


149 


5556 


35 


0.819 


5320 


0.958 


0.951 


5284 


36 


150 


4687 


20 


0.940 


4553 


0.971 


0.975 


4570 


-17 


151 


5094 


20 


0.940 


4918 


0.965 


0.975 


4967 


-49 


159 


5721 


25 


0.906 


5545 


0.969 


0.968 


5538 


7 


160 


2728 


25 


0.906 


2614 


0.958 


0.968 


2641 


-27 


161 


4584 


13 


0.974 


4484 


0.978 


0.985 


4515 


-31 


162 


5221 





1.000 


5124 


0.981 


1.000 


5221 


-97 



47 



48 



OBSERVATIONS AND RESULTS EST PHYSICAL OCEANOGRAPHY 



weight at the end of the wire, which was not kept constant, 
and by the speed of lowering. The depth factor corre- 
sponding to any given wire angle can be read off from 
the curve in figure 1 and the wire depth obtained by mul- 
tiplying the wire, length with this factor. 

In order to estimate the probable errors of the wire 
depths which have been determined by this method, such 
wire depths have been computed in the cases in which 
the depth was determined independently by thermometer 
and entered in table 1 together with the differences be- 
tween the wire depths and the thermometer depths. 
These differences, which are represented graphically in 
figure 2, increase with increasing depth, which means 
that the error in the wire depth increases with depth. 
All points except three fall inside the two straight lines 
which have been drawn in the figure, representing a dif- 



ference of 2.5 per cent of the depth. Of this difference 
0.5 per cent can be regarded as owing to uncertainty in 
the thermometer depth and the maximum error of the 
wire depth is thus about 2 per cent of the depth. It is 
evident from the graph and from the values in the table 
that the error of the wire depth as a rule is considerably 
smaller, especially if the depth is small. The result 
must be regarded as very satisfactory, considering that 
wire angles greater than 40° frequently occurred. 

Summarizing the preceding discussion it can be 
stated that when sounding with piano wire has been under- 
taken and the wire length and wire angle recorded, the 
wire depth can be found by multiplying the wire length by 
a factor which is read off from figure 1. The wire depth 
which has been computed by this method has a maximum 
error of 2 per cent. 



*• ^ 

■Q n illll M I I N I M II M T M I I H 1II III I I N II II M llll I N I I I I I I I M M l II II I I I II II I llll I I II till II I II I I 1 1 1 || II II llllll t l M il I III II III 




FIG. I -RELATION BETWEEN WIRE ANGLE AND FACTOR BY WHICH WIRE LENGTH MUST BE 
MULTIPLIED TO OBTAIN DEPTH WHEN SOUNDING WITH PIANO WIRE 




-200 
L 6000 



FIG. 2- THERMOMETER DEPTH (D t ) MINUS WIRE DEPTH {dj AS 
A FUNCTION OF DEPTH 

40 



SONIC DEPTH WORK 



During the summer of 1927 while the Carnegie was 
being overhauled prior to the beginning of her seventh 
cruise, sonic depth -finding equipment loaned by the 
United States Navy Department was installed. This 
equipment was of a type well suited for deep-sea sound- 
ing and consequently fitted the needs of the Carnegie . A 
Fessenden type of oscillator having a 30-inch steel dia- 
phragm was located in the keel below the after part of 
the engine room. This oscillator, which was the source 
of sound of 540-cycle frequency, was actuated electro- 
magnetically, being supplied with alternating current of 
540-cycle frequency at 180 volts and direct current at 
115 volts. A 5-kilowatt remote-controlled motor gener- 
ator set for the alternating-current supply was located 
in the toolroom just off the engine room on the port side; 
the control panel was located in the engine room near 
the forward end. Six Navy hydrophones, any three of 
which could be used at one time, were located along the 
port garboard ,strake below the chartroom. 

The depth finder proper was located in the control 
room (a deckhouse on the port side of the forward end of 
the quarter-deck). The depth finder acted as the clock 
for measuring the time required for the sound to travel 
from the surface to the bottom and return. It consisted 
of a tuning fork-controlled rotary converter which drove 
a large bakelite disc at constant speed. Riding on, and 
driven by this bakelite disc, was a smaller accurately 
machined brass disc mounted on a splined shaft carry- 
ing a series of commutators which made and broke the 
electrical circuit of a relay; this, in turn, operated the 
oscillator, thus sending out signals at periodic intervals, 
By means of a calibrated screw the radius at which the 
brass disc rode on the bakelite disc, and consequently 
the time interval between signals, was continuously var- 
iable between limits set by the dimensions .of the bake- 
lite disc. The outgoing signals and the returned echoes 
were audible in the telephone receivers, and in taking a 
sounding the position of the brass disc on the bakelite 
disc was adjusted until the outgoing signals occurred 
simultaneously with the returned echoes of the immedi- 
ately preceding signals. Under this condition, the time 
required for a signal to travel to bottom and return was 
the same as the time interval between two successive 
signals. A dial operated by the calibrated screw indi- 
cated, in effect, the latter time interval. 

A table, based on an arbitrarily selected sound 
velocity of 1450 meters per second, was made for con- 
verting dial readings into approximate depths, due 
consideration being given the horizontal distance be- 
tween oscillator and hydrophones. As the velocity of 
sound in sea water is a variable depending chiefly on 
temperature, salinity, and pressure, the approximate 
depth was then multiplied by the suitable correction 
factor selected from a table applicable to the area in 
which the sounding was taken. To the value thus ob- 
tained, a further correction for draft was applied. 

As originally installed, the outgoing signal was 
brought to the receivers from the secondary of an air- 
core transformer, the primary of which was in the al- 
ternating-current circuit of the oscillator. Thus there 
would be heard, first the electrically conducted impulse 
of the outgoing signal, then the outgoing signal as a di- 
rect sound wave picked up by the hydrophones, and finally 



the reflected sound wave as picked up by the hydrophones. 
As the first two arrived but a short time apart, it re- 
sulted in a blurred sound of considerable intensity, which 
had to be matched in time of arrival with a fainter sound 
of shorter duration. Later on the arrangement was 
changed and the air -core transformer eliminated, so 
that the outgoing signal was registered only as the direct 
sound wave picked up by the hydrophones. This resulted 
in a sharper outgoing signal in the receivers, and a con- 
sequently greater ease and accuracy in getting a balance. 
After this change in arrangement, a further constant cor- 
rection of half the distance between oscillator and hydro- 
phones was added. 

The correction factors applicable to a certain local- 
ity were grouped into a table of ratios of the average 
velocity of sound down to the applicable depth, to the 
basic velocity of 1450 meters per second. These were 
based on the British Admiralty Hydrographic Department 
Publication No. 282 entitled "Tables of the velocity of 
sound in pure water and sea-water for use in echo-sound- 
ing and sound-ranging." The variation in pressure at a 
given depth, due to the variation in gravity with latitude, 
was considered to be small enough to be disregarded. 
The range in temperature normally encountered is from 
-2° to +30° C, whereas the salinity range is within 31.00 
to 38.00 parts per thousand. Correction factors were 
computed for salinities of 31.00 and 38.00 parts per 
thousand and all even degrees of temperature from -2° 
to +30° C, using tables 2 and 3 of the British Admiralty 
publication cited above. From these factors a set of 
straight-line curves was drawn, one curve for each de- 
gree. Although the isothermal variation of velocity with 
salinity is not linear, it was sufficiently so for this pur- 
pose. 

Curves based on the data in table 1 give the correc- 
tion factor to the basic velocity at any salinity and tem- 
perature at atmospheric pressure. The amounts to be 
added to the values derived from table 1 because of 
pressure effect, as taken from table 4 of the British Ad- 
miralty publication, are shown in table 2. 

A set of correction factors was prepared every two 
days from actually measured temperatures and salinities 
in the following manner. Vertical distribution curves of 
temperature and salinity were plotted, and from these 
curves were scaled the values at the nominal depths (in 
meters) of 0, 25, 50, 75, 100, 200, 300, 400, 500, 1000, 
1500, 2000, etc. The temperature and salinity measure- 
ments usually extended to depths of from 2000 to 4000 
meters. The vertical distribution curves were extrapo- 
lated to depths ordinarily about 500 meters greater than 
the deepest soundings obtained in the area in question. 
The extrapolations were made with the help of composite 
curves based on measurements made in areas where the 
deep water was homogeneous. These group extrapola- 
tions are discussed in the section on sounding velocity. 
From the velocity correction curves, values of correc- 
tions were obtained for th» conditions of temperature 
and salinity prevailing at the nominal depths. To these 
were added the corrections, due to pressure, corre- 
sponding to the appropriate depth and temperature, and 
taken from table 2. The sum of these two corrections 
was entered in a column headed "velocity corrections" 
opposite the proper depth. The procedure for getting the 



51 



52 



OBSERVATIONS AND RESULTS IN PHYSICAL OCEANOGRAPHY 



Table 1. Data used for graphs to determine correction 

factors to basic velocity at any salinity and 

temperature at atmospheric pressure 



Tem- 


Salinity 3 1 .00 per mille 


Salinity 38.00 per mille 


pera- 
ture, 


Velocity, 


[Velocity] * 
L 1450 J 


Velocity, 


Velocity 


-1 


°C 


m/sec 


m/sec 


L 1450 J 




-2 


1430.96 


-.0131 


1440.04 


-.0069 


-1 


1435.68 


-.0099 


1444.72 


-.0036 





1440.30 


-.0067 


1449.30 


-.0005 


1 


1444.92 


-.0035 


1453.88 


+.0027 


2 


144G.34 


-.0005 


1458.26 


+.0057 


3 


1453.76 


+.0026 


1462.64 


+.0037 


4 


1458.08 


+ .0056 


1466.92 


■t 0117 


5 


1462.20 


+ .0084 


1471.00 


+.0145 


6 


1466.34 


+.0113 


1475.08 


+.0173 


7 


1470.38 


+.0141 


1479.06 


+.0200 


8 


1474.32 


+.0168 


1482.94 


+.0227 


9 


1478.16 


+.0194 


1486.72 


+.0253 


10 


1481.90 


+.0220 


1490.40 


+ .0279 


11 


1485.56 


+.0245 


1493.94 


+.0303 


12 


1489.12 


+.0270 


1497.38 


+.0327 


13 


1492.68 


+.0294 


1500.82 


+.0350 


14 


1496.04 


+.0317 


1504.06 


+.0373 


15 


1499.30 


+.0340 


1507.20 


+.0394 


16 


1502.52 


+.0362 


1510.38 


+.0416 


17 


1505.54 


+.0383 


1513.36 


+.0437 


18 


1508.56 


+.0404 


1516.34 


+.0458 


19 


1511.48 


+.0424 


1519.22 


+.0477 


20 


1514.30 


+.0443 


1522.00 


+.0497 


21 


1517.04 


+.0462 


1524.68 


+.0515 


22 


1519.78 


+.0481 


1527.36 


+.0534 


23 


1522.42 


+.0499 


1529.94 


+.0551 


24 


1524.96 


+.0517 


1532.42 


+.0568 


25 


1527.50 


+.0534 


1534.90 


+.0585 


26 


1529.92 


+.0551 


1537.28 


+.0602 


27 


1532.24 


+.0567 


1539.56 


+.0618 


28 


1534.56 


+.0583 


1541.84 


+.0633 


29 


1536.88 


+.0599 


1544.12 


+.0649 


30 


1539.00 


+.0614 


1546.20 


+.0663 



correction factors applicable to the various depths was 
from this point on a more or less obvious one of taking 
means. A specimen set of computations of correction 
factors is reproduced in table 3. 

Criticism may be made of the arbitrary selection of 
the basic velocity of 1450 meters per second for the 
compilation of calibration tables. Consideration was 
given to the selection of some velocity which would have 
some significance other than merely being the base for 
a set of tables. For instance, such as the velocity of 
sound in water of 35.00 per mille salinity, 0° C temper- 
ature, and atmospheric pressure. So far as could be 
learned, however, practice had not crystallized to the 
point of selecting such a velocity which could be consid- 
ered as stindard, and as any velocity might be used 
equally as well as any other velocity, it was considered 
best for the purpose to select a figure which was approx- 
imately a round number, was somewhere near the true 
velocity, and would give corrections which would be ad- 
ditive in nearly all cases. It was for these reasons that 
1450 meters per second was the velocity selected. 

An estimate of the accuracy of each sounding was 
made and recorded at the time of the measurement. The 
method of arriving at these estimates may be of interest. 
The rotary converter and its controlling tuning fork were 
of 60-cycle frequency. As long as synchronism was 
maintained, the two had to maintain a phase relation 
which was constant within a quarter -cycle, and it is 



probable that the successful synchronizing range was 
about one-eighth of a cycle. This meant that relative to 
the tuning fork, the rotating parts were varying in phase 
by a maximum of 1/480 second or about 3 meters in 
distance. As the distance traveled was twice the depth, 
the uncertainty in depth due to this cause was about 1.5 
meters. As there was no temperature control or com- 
pensation on the tuning fork, and as there was about 
10° C range on either side of the mean, and as the tuning- 
fork rate had a temperature coefficient of about 0.007 
per cent per degree centigrade, it was considered that 
the time intervals indicated were subject to an error of 
0.1 per cent. Further, there was an uncertainty of the 
dial setting within which the outgoing and returning sig- 
nals sounded as one to the operator. This uncertainty 
was converted into depth and if greater than 0.1 per cent 
and greater than 1.5 meters, it was recorded as the un- 
certainty of the measurement. If it was less than 0.1 
per cent but greater than 1.5 meters, 0.1 per cent of the 
sounding was recorded as the uncertainty. And if the 
distance 1.5 meters was greater than both the uncertain- 
ty of setting and 0.1 per cent, then it was recorded as 
the uncertainty of measurement. It was thought that 
this was a reasonable procedure of estimating the accu- 
racy of soundings. This is assuming, however, that the 
frequency of the tuning fork was accurately adjusted to 
60 cycles per second, that the sounding velocity used 
was accurate, that the sounding distance was vertical, 
and that no gross errors were involved. The conditions 
of temperature and salinity at nearby oceanographic 
stations are on record, and if in the future it is found 
that the velocities used were inaccurate, corrections 
may be made. Very often echoes would be reflected 
from more than one surface. In such cases the first 
echo to return was selected as being from that surface 
which was most nearly vertically beneath the ship. Be- 
cause of the comparatively gentle slopes of the ocean 
bottom, such a procedure is probably not greatly in er- 
ror in soundings at sea, although it is recognized that in 
steep gradients, such as are encountered in certain ap- 
proaches to land, the error may be considerable. Gross 
errors are possible when the returned echoes are 
matched with second or third succeeding signals instead 
of with the immediately succeeding signal, thus giving 
one-half, or one-third, the actual depth. Such errors 
are easily avoidable by sending single signals in order 
to determine the order of magnitude of the depth. As 
the single signal was usually used to determine the num- 
ber of reflecting surfaces and the number of echoes, 
there was little possibility of gross errors entering the 
Carnegie results from this cause. Actually, the fre- 
quency of the tuning fork was not accurately adjusted to 
60 cycles par second and corrections, which will be 
dealt with below, have been applied to the soundings taken 
with the sonic depth finder. 

A program of sounding every four hours was attempt- 
ed. During such times as the ship was becalmed or 
making little headway, soundings were taken about every 
ten miles. This program was, in general, followed but 
in areas of rapidly changing depth more frequent sound- 
ings were made. Other deviations from this schedule 
sometimes occurred to avoid interference with pilot- 
balloon ascensions, or radio schedules, and occasionally 
because of the press of other work. Short interruptions 
to the sounding program were sometimes caused by the 
necessity of making repairs to the depth finder or to the 
gasoline engine which drove the main generator. The 



SONIC DEPTH WORK 



53 



Table 2. Amounts to be added to correction factor because of pressure effect 



Depth 

in 
meters 



Tempera- 
ture, C C 



From 



To 



Amount 



Depth 

in 
meters 



Tempera- 
ture, °C 



From 



To 



Amount 



25 


-2 


+ 25 


.0003 


500 


-2 


+ 5 


.0063 


50 


-2 


+ 25 


.0006 


1000 


-2 


+ 5 


.0126 


75 


-2 


+ 25 


.0009 


1500 


-2 


+ 5 


.0188 


100 


-2 


+ 25 


.0012 


2000 


-2 


+ 5 


.0250 


200 


-2 


+ 25 


.0025 


2500 


-2 


+ 3 


.0313 


300 


-2 


+ 25 


.0037 


3000 


-2 


+ 3 


.0375 


400 


-2 


+ 25 


.0050 


3500 


-2 


+ 3 


.0437 



Depth 

in 
meters 



Temperature, °C 



1 



4000 


.0499 


.0499 


.0499 


.0499 


.0498 


4500 


.0561 


.0561 


.0560 


.0559 


.0559 


5000 


.0623 


.0621 


.0621 


.0621 


.0619 


5500 


.0684 


.0683 


.0683 


.0681 


.0680 


6000 


.0745 


.0744 


.0743 


.0742 


.0741 


6500 


.0806 


.0805 


.0803 


.0801 


.0800 


7000 


.0866 


.0865 


.0863 


.0881 


.0859 


7500 


.0926 


.0925 


.0923 


.0920 


.0918 


8000 


.0986 


.0984 


.0981 


.0979 


.0977 


8500 


.1046 


.1043 


.1040 


.1037 


.1034 


9000 


.1104 


.1101 


.1099 


.1095 


.1092 


9500 


.1162 


.1159 


.1156 


.1153 


.1150 



Table 3. Specimen determination of correction factors 
Station 93; latitude 14° 4113 south, longitude 167°40:8 west; Sunday, March 31, 1929; Comp. F.M.S. 



D 


T K 


S 


Vel. 
corr. 


Mean corr. of layer 


Sum 

of 

means 


Corr. 


25 


100 


500 


fact. 


m 


• 


o/oo 

















28.74 


34.71 


.0622 








1.0624 


1.0622 


5 


28.75 


34.68 




.0624 






2.1248 




25 


28.75 


34.76 


.0625 


.0624 


.0624 




3.1872 


1.0624 


50 


28.50 


34.78 


.0624 


.0624 




4.2495 


1.0624 


75 


28.05 


35.40 


.0624 


.0623 






2.1212 a 


1.0624 


100 


27.55 


35.85 


.0622 




.0588 


.0485 


3.1715 a 


1.0624 


200 


22.65 


36.04 


.0555 




.0503 


4.2112 a 


1.0606 


300 


16.90 


35.28 


.0451 




.0397 




5.2425 a 


1.0572 


400 


11.70 
8.90 


34.75 
34.57 


.0343 
.0283 




.0313 






1.0528 


500 


1.0485 


1.0485 


700 


5.65 


34.38 








.0246 


2.0731 




1000 


3.95 


34.47 


.0210 






.0222 


3.0953 


1.0366 


1500 


2.70 


34.52 


.0235 






.0258 


4.1211 


1.0318 


2000 


2.15 


34.57 


.0282 






.0310 


5.1521 


1.0303 


2500 


1.90 


34.63 


.0337 






.0366 


6.1887 


1.0304 


3000 


1.70 


34.66 


.0394 






.0424 


7.2311 


1.0314 


3500 


1.60 


34.67 


.0453 






.0481 


8.2792 


1.0330 


4000 


1.40 


34.67 


.0509 






.0535 


9.3327 


1.0349 


4500 


1.10 


34.67 


.0561 






.0592 


10.3919 


1.0370 


5000 


1.10 


34.67 


.0622 






.0653 


11.4572 


1.0392 


5500 


1.10 


34.67 


.0684 






.0714 


12.5286 


1.0416 


6000 


1.10 


34.67 


.0744 










1.0440 


6500 


















7000 


















7500 


















8000 



















l These values and all values below heavy line by extrapolation. 



54 



OBSERVATIONS AND RESULTS IN PHYSICAL OCEANOGRAPHY 



longest and most serious interruption was caused by the 
failure of the oscillator on November 3, 1928. It was 
not until Callao was reached that repairs to the oscilla- 
tor could be made, since such repairs required dry- 
docking. Consequently, no accurate soundings were 
made between November 3, 1928 and February 5, 1929. 
Beginning November 14, 1928 rough soundings were 
made with an improvised shotgun. A steel breech just 
long enough to hold a 16-gage shotgun shell was screwed 
into one end of a length of brass pipe. The pipe acted as 
a holder and also as a guide for a heavy steel firing pin 



which was dropped into the upper and open end of the 
pipe, the shell end being held a foot or two below the 
surface. The hydrophones were used to pick up the 
echo and a stop wtach used to measure the elapsed time. 
Soundings were taken in this manner twice a day. These 
were only approximate because of the inaccuracy of the 
stop-watch measurement and because of the uncertainty 
of the velocity of a sound set up by an explosion. It was 
a case of half a loaf being better than none, however, 
and the device materially assisted in the routine occupa- 
tion of oceanographic stations. 



CORRECTIONS OF SONIC DEPTHS DETERMINED ON BOARD THE CARNEGIE 
ON ACCOUNT OF ERRORS IN THE TIMING 



Depth was measured on board the Carnegie by three 
different methods, namely, by thermometers which were 
reversed at a short distance from the bottom, by wire 
soundings, and by sonic methods. The accuracy of 
soundings by thermometers or wire has been discussed 
and it has been shown that the depth obtained by ther- 
mometers can be regarded as reliable within +0.5 per 
cent; the depths by wire soundings are reliable within 
+ 2.0 per cent. 

The accuracy of the depths determined by the sonic 
depth finder would be considerably greater than that of 
the other methods, supposing that no instrumental er - 
rors were present. Whether or not such errors oc- 
curred can be decided by examining the cases in which 
the depth was determined by thermometers or wire 
sounding close to a locality where the depth was meas- 
ured by the sonic method. When making such an exami- 
nation one must expect considerable variation in the 
results obtained by the different methods. This is part- 
ly because of the limited accuracy of the wire soundings, 
and partly because the sonic depth was not determined 
simultaneously with the other determination, for which 
reason irregularities of the bottom may give rise to 
discrepancies. The mean values obtained by the differ- 
ent methods, however, ought to agree if no systematic 
errors occur in the sonic depths. 

When comparing the results by the different meth- 
ods, it is to be noted that the timing of the sonic depth 
finder was readjusted February 19, 1929, and the com- 
parison, therefore, must be made separately for the 
periods before and after this date. Table 1 gives the 
approximately simultaneous values of sonic depths and 
depths determined either by thermometers or by wire. 
The latter two are entered under the heading "true 
depth." The depths by thermometers have been en- 
tered, if available, because of the greater accuracy. 
The sonic depths entered in the table are derived from 
those sonic soundings which were made at the shortest 
distances from the locations at which the depths were 
determined by other methods. The last two columns of 
the table give the ratios between the true depths and the 
sonic depths, that is, the factor by which the sonic depth 
must be multiplied to obtain the true depth. The factors 
are arranged according to the character of the bottom. 
The bottom was regarded as being fairly regular when 
the difference between the two nearest sonic depths was 
less than 100 meters and the resulting factors are en- 
tered in the first of the last two columns. The bottom 
was regarded as irregular when the difference between 
the two nearest sonic depths exceeded 100 meters, and 
the resulting factors are entered in the last column. 

It is seen that the sonic depths usually are greater 
than the depths by thermometers or wire. The bottom 
was extremely irregular or the wire depth was uncertain 
in a few outstanding cases, as is evident from the foot- 
notes to the table. Omitting the nine cases indicated by 
these footnotes, fifty -nine approximately simultaneous 
values of sonic depths and thermometer or wire depths 
remain for comparison, twelve of which were obtained 
before, and forty-seven after, the readjustment of the 
timing February 19, 1929. The further discussion will 
be based on these fifty-nine cases only. 



During the first period, using all twelve values, the 
mean sonic depth is 2871 meters, the mean true depth is 
2683 meters, and the timing factor is 0.935. Using only 
the eight cases in which the depth was determined by 
means of thermometers, the mean sonic depth is 2327 
meters, the mean true depth is 2197 meters, and the 
timing factor is 0.944. 

The available data are much greater for the second 
period and a more detailed comparison between the 
sonic depths and the depths obtained by other methods 
can be made. The data of table 1 have been summarized 
in table 2, which gives the ratios between true depth and 
sonic depth for a number of different groups. The mean 
ratios were derived both from the mean depths and by 
forming the means of the single ratios. In the latter 
case the probable error of the mean value has been in- 
dicated. 

From table 2 it is evident that the mean value of the 
ratio is practically independent of the grouping and also 
that the mean ratio, which is computed from the single 
ratios, agrees with the ratio of the mean depths. The 
latter feature shows that the ratio is nearly independent 
of depth. The mean errors in the last column show that 
the scattering of the single values of the ratio is smaller 
when the bottom is regular than when it is irregular, and 
also that the scattering is smaller when the true depth 
was determined by thermometers instead of by wire. 
Both these features should be expected. The irregular 
variations of the bottom and the greater error of the 
wire depths give rise to greater discrepancies. 

From the preceding discussion it appears that the 
depths which were determined by means of the sonic 
depth finder during the period from February 19 to No- 
vember 18, 1929 must be multiplied with a constant fac- 
tor in order to give the true depth and the same evident- 
ly applies to the first period from May 13, 1928 to Feb- 
ruary 19, 1929. Considering that the most consistent 
results were obtained by comparison with depths which 
were determined by thermometers when the bottotr was 
fairly regular, the following correction factors have 
been adopted for the soundings taken with the sonic depth 
finder: (1) May 13, 1928 to February 19, 1929, correc- 
tion factor 0.944 and (2) February 19 to November 18, 
1929, correction factor 0.964. The probable error of 
the latter factor is not greater than +0.003, but the 
probable error of the former is perhaps +0.009. 

The instrumental error which makes application of 
these corrections to the sonic depths necessary must 
arise from an error of timing of the system. An error 
in the timing would lead to error in the sonic depth, 
which would be approximately proportional to the depth 
and therefore could be approximately eliminated by 
multiplication of the computed sonic depth with a con- 
stant factor. The fact that the correction factor was 
evidently changed when the timing was readjusted also 
indicates that the discrepancies arise from errors in 
timing. An error in timing should strictly be eliminated 
by correcting the time of echo before computing the 
sonic depth, but it can be shown that only an insignificant 
error is introduced by computing the sonic depth on the 
basis of the observed time of echo and correcting this 
computed depth by multiplication by a constant factor. 



55 



56 



OBSERVATIONS AND RESULTS IN PHYSICAL OCEANOGRAPHY 



Table 1. Comparison of sonic depths with true depths as determined on the Carnegie. 1928-1929 



Station 
no. 



Sonic 
sounding 



Sonic 
depth 



True depth 



Thermom- 
eter 10. 5 
per cent 



Wire 

±2 

per cent 



Ratio (true/sonic) 



Bottom 
regular 



Bottom 
irregular 



7 
9 

10 

12 

13 

27 

30 

37 

38 

72 

74 

75 

76 

77 

78 c 

79 

79 

80 

81 

82 

83 

84 

85 

86 

87 

94 

96 

97 
108 
10? 
110 
111 
112 
115 
116 
117 
119 
127 
127 
128 
128 
131 
132 
133 
134 
135 
136 
137 
138 
139 
140 
141 
142 
145 
146 
147 
148 
149 
150 
151 
153 
155 
156 
157 
159 
160 
161 
162 



64 

99 

114 

150 

158 

262 

296 

354 

360 

485 

496 

506 

517 

529 

536 

547 

547 

559 

572 

585 

596 

609 

622 

658 

672 

759 

779 

789 

921 

932 

943 

956 

960 

980 

989 

997 

1015 

1094 

1 094 

1108 

1108 

1136 

1151 

1162 

1172 

1179 

1187 

1195 

1206 

1218 

1227 

1239 

1249 

1280 

1289 

1300 

1310 

1321 

1332 

1344 

1365 

1385 

1396 

1415 

1453 

1470 

1481 

1490 



m 

495 
919 
3210 
2849 
145 
2831 
4988 
3500 
2512 
4819 
4565 
3912 
3387 
4275 
3601 
3177 
3177 
3601 
3298 
3700 
4158 
4266 
3906 
2100 
4432 
4917 
5524 
5523 
4488 
5174 
3172 
6106 
4445 
5636 
5902 
5525 
5376 
4296 
4296 
4118 
4118 
4597 
4460 
4545 
4676 
4829 
4798 
5339 
5659 
5262 
4964 
5847 
5916 
5728 
5097 
4893 
4993 
5377 
4284 
5062 
5226 
5173 
5247 
4134 
5607 
2699 
2624 
5248 



m 

454 

882 
3031 
2792 

126 

4703 
3324 

2264 



m 



2571 



4480 

4141 a 

3480 u 

2778 b 

4094 

3337 

3064 

3116 

3515 

2953 



3631 
4121 
2132 d 



3966 
3791 

4315 

4760 

5269 

5253 

3573 e 

5252 



3036 
3 931 a 



5296 

4034 
4018 
3785 
3826 
4418 
4251 
4426 
4528 
4695 

5208 
5382 
5030 
4762 
5667 
5787 



6008 

5396 
5545 

5198 



4713 



4756 



5320 

4553d 

4918 



5584 



5545 
2614 
4484 
4124 



4840 
4835 



5003 
5304 
4953 
4693d 



0.917 



0.943 



0.907a 



0.927 



0.976 



0.954 
0.966 
0.971 



0.974 
0.968 
0.954 



1.015 f 
6.985 



0.940 
0.959 



0.939 
0.935 



0.961 
0.953 



0.972 
0.982 
0.975 



0.969 
0. 975 



0.989 



0.957 
1.025S 



0.969 
0.970 



0.960 
0.944 
0.980 
0.869 
0.908 



0.950 
0.901 
0.930 



0.890 u 
0.820 b 
0.958 



0.9*4 
0.981 



0.895 
0.981 



1.015 d 



0.951 
0.796 e 



0.957 



0.884 a 
0.957 



0.967 



0.919 
0.929 



0.974 
0.968 



0.951 
0.956 
0.959 



0.978 



0.933 

0.989- 

0.968 



1.063 d 
0.972 



0.944 

1.135 d 

0.989 



0.976 



a Original record indicates wire length somewhat uncertain. b Station probably on peak, sonic 

depths being much greater on either side. c Timing sonic depth finder readjusted between stations 77 
and 78. d station probably on slope, sonic depths being much greater on either side. e Sonic depths 

show irregular bottom but not such that so large a discrepancy should be expected. ^n the slope ot 

Fleming Deep. gWire depth uncertain on account of heavy current and resulting large wire angle. 



CORRECTIONS OF SONIC DEPTHS ON ACCOUNT OF ERRORS IN TIMING 



57 



The velocity of sound, determined from experiments 
in which the source of sound is an explosion, is greater 
than when the source used is a diaphragm vibrating with 
constant amplitude. Further, the difference in velocities 
is dependent on the distance involved and the violence of 
the explosion. This has been explained as being the re- 
sult of a sound wave train of normal velocity superim- 
posed on an explosive wave which suffers great attenua- 
tion. On this assumption the greater initial velocity is 
a transient phenomenon, after the disappearance of which 
the velocity becomes normal. 

Following this line of reasoning, one should expect 
to find that the soundings taken on the Carnegie with the 
improvised shotgun would have to be corrected for this 
effect. On thirty-four occasions the time of echo was 
measured for more than the first echo. These times of 
echo were accordingly investigated and are given in 
table 3. In one case the time was measured from the 
explosion to the return of the fourth and fifth echoes, and 
in thirty-three cases times were measured for first and 
second echoes. Of the thirty-three cases there were two 
in which the time was recorded as being doubtful, and in 
another case an error of one second was apparently 
made in reading the stop watch for the time of the sec- 
ond echo. In the remaining thirty cases the time for the 
first echo was subtracted from the time for the first two 
echoes to obtain the time for the second echo. The dif- 
ferences between the times for the first and second 
echoes were then taken. In the case where the times for 
four and five echoes were measured, it was assumed 
that the times for the second and succeeding echoes 
were the same. From this, the time for the first echo 
was computed and compared with the time for the fifth 
echo. In these thirty -one cases the average difference 
between the times for the first and succeeding echoes 
was 0.113 seconds. 

The echo times have, therefore, been corrected on 
the assumption that the times of all first echoes, as 
measured, were too small by this amount. This was 
done by adding 85 meters to the gross depths based on 
first echoes alone, 64 meters to the gross depths based 
on first and second echoes, and 42 meters to the gross 
depthsbased on second echoes alone. The shotgun sound- 
ings adjusted for this correction were then compared 



with the wire depths and depths determined from pres- 
sure thermometers at the twenty oceanographic stations 
where such measurements were made. Of the twenty 
comparisons, the one made on Merriam Ridge (station 
67) has been omitted because of the steep bottom slope 
in this vicinity. Because of the great distances between 
shotgun soundings, there is no way of telling when the 
bottom was regular and when irregular except in the 
previously mentioned case of Merriam Ridge. There- 
fore, as the shotgun soundings and accepted depths are 
only approximately simultaneous, a greater scatter must 
be expected than was found in the comparison of sonic 
depth finder soundings with accepted depths. A greater 
scatter must also be expected because a stop watch 
measurement of echo time is not as precise as an echo 
time measured by the sonic depth finder. Table 4 gives 
the approximately simultaneous depths as determined by 
wire and pressure thermometers and as given by the 
shotgun soundings corrected for greater intial velocity. 

Comparison of the shotgun depths with correspond- 
ing wire and thermometer depths shows the shotgun sound- 
ings consistently greater (see fig. 1). The mean shotgun 
depth for the nineteen cases, excluding station 67, is 
3621 meters, and the mean wire depth is 3471 meters, 
giving a ratio of means of 0.C58+. The mean of the sin- 
gle ratios is 0.960- with a probable error of +0.006. 

In view of this a timing factor of 0.958 has been 
adopted and used for the correction of shotgun soundings 
after they were adjusted for the greater initial velocity 
resulting from the explosive character of the source of 
the sound. This makes the assumption that the stop 
watch had a large gaining rate. In May 1928 the stop 
watch was compared with a chronometer at the beginning 
and end of a two -hour run, and it checked so closely that 
it was considered permissible to use it as a time stand- 
ard in the calibration of the depth finder timing. The 
depth finder was then adjusted until it was in agreement 
with the stop watch over a period of about fifteen minutes. 
The depth finder was similarly adjusted in February 1929 
after it had been repaired and overhauled. The same 
stop watch was used in measuring the echo times for the 
shotgun soundings. In all three instances, that is, during 
the period from May 1928 to February 1929, the period 
from February 1929 to November 1929, and in the shotgun 



Table 2. Summary of comparison between sonic depths and thermometer or wire depths 

at stations 78 to 162 





No. 
of 


Mean 


depth 


Ratios 


Means of sin- 


Group 


in meters 


of 


gle ratios and 

their probable 

errors 




cases 


Sonic 


True 


mean 
depths 


Depth by thermometer, 












bottom regular 


12 


4680 


4510 


0.964 


0.963 +0.0029 


Depth by thermometer, 












bottom irregular 


14 


4796 


4610 


0.961 


0.960 +0.0038 


Depth by wire, 












bottom regular 


12 


4825 


4650 


0.964 


0.964 +0.0035 


Depth by wire, 












bottom irregular 


9 


4591 


4401 


0.959 


0.957 +0.0061 


Bottom regular 


24 


4752 


4580 


0.964 


0.963 +0.0022 


Bottom irregular 


23 


4716 


4528 


0.960 


0.959 +0.0032 


Depth by thermometer 


26 


4742 


4564 


0.962 


0.962 +0.0024 


Depth by wire 


21 


4724 


4543 


0.962 


0.961 ±0.0032 


All values 


47 


4734 


4555 


0.962 


0.961 +0.0019 



58 



OBSERVATIONS AND RESULTS IN PHYSICAL OCEANOGRAPHY 



Table 3. Showing difference in time required for first and succeeding echoes 



Sound- 
ing 
no. 


Time of 


Mean time of 


Sound- 
ing 
no. 


Time of 


Mean time of 


First 
echo 


First 

two 

echoes 


First 
echo 


Second 
echo 


Differ- 
ence 


First 
echo 


First 

two 

echoes 


First 
echo 


Second 
echo 


Differ- 
ence 



363 


3.2 


9.6 


3.2 


6.4 


+ 3. 2a 


441 


4.7 


364 


5.2 


10.4 










4.6 




5.3 


10.1 


5.25 


5.00 


-0.25 


445 


4.3 


366 


5.5 


12.2 


5.5 


6.7 


+ 1.2b 




4.2 


369 


4.5 


9.5 








446 


4.7 




4.5 


9.8 


4.50 


5.15 


+ 0.65a 


447 


5.0 


378 


4.0 


7.9 


4.0 


3.9 


-0.1 


450 


4.8 


379 


4.0 


7.5 










4.9 




3.8 


7.7 


3.90 


3.70 


-0.20 


451 


4.8 


380 


4.2 


8.2 


4.2 


4.0 


-0.2 




4.8 


393 


4.2 
3.9 


8.2 
8.2 








452 


4.8 
4.7 




4.4 


8.6 


4.17 


4.17 


+ 0.00 


453 


5.0 


395 


4.5 


9.0 








460 


1.8 




4.4 


8.9 


4.45 


4.50 


+ 0.05 




1.5 


396 


4.0 


8.5 


4.0 


4.5 


+ 0.5 


463 


5.5 


397 


3.8 


7.6 


3.8 


3.8 


+ 0.00 


464 


5.5 


403 


3.5 


7.7 


3.5 


4.2 


+ 0.7 


466 


5.8 


414 


4.2 


8.7 










5.8 




4.2 


8.3 


4.20 


4.30 


+ 0.10 


467 


5.8 


421 


5.2 


10.4 


5.2 


5.2 


±0.00 




5.5 


431 


5.0 


10.1 


5.0 


5.1 


+ 0.1 


470 


5. 


432 


5.2 


10.0 


5.2 


4.8 


-0.4 




5.6 


438 


4.8 


10.2 








472 


5.8 




5.2 


10.2 


5.00 


5.20 


+ 0.20 




5.6 C 


440 


4.7 










475 


3.1c 






9.5 


4.7 


4.8 


+ 0.1 







9.6 








9.6 


4.65 


4.95 


+ 0.30 


8.7 








8.6 


4.25 


4.40 


+ 0.15 


9.7 


4.7 


5.0 


+ 0.3 


10.2 


5.0 


5.2 


+ 0.2 


10.1 








10.2 


4.85 


5.30 


+ 0.45 


9.8 








9.9 


4.80 


5.05 


+ 0.25 


9.8 








9.7 


4.75 


5.00 


+ 0.25 


10.3 


5.0 


5.3 


+ 0.3 


3.5 








3.5 


1.65 


1.85 


+ 0.20 


11.0 


5.5 


5.5 


+ 0.00 


11.1 


5.5 


5.6 


+ 0.1 


11.4 








11.6 


5.80 


5.70 


-0.10 


11.5 








11.2 
10.1 
10.1 


5.65 


5.70 


+ 0.05 


5.05 


5.05 


±0.00 


11.7 








11.8, 


5.70 


6.05 


+ 0.35 


3.9 d 


0.70 


0.80 


+ 0.10 



Mean and probable error= +0.113 ±0.028 



a Time questioned in original record. 

c Time for first four echoes. 



^Time of second echo apparently in error by one second. 
^Time for first five echoes. 



soundings, the ratios of true depth to indicated sonic 
depth have been of the same order of magnitude and 
less than unity. This can probably be reconciled with 
the comparison of stop watch and chronometer by con- 
sidering that the stop watch had a faster rate during the 
first part of a run than during the latter part, such as 
the second hour, and that the initial fast rate was main- 
tained during the first fifteen minutes. This seems to be 
be a reasonable assumption, and on such a basis the dif- 
ferences between the timing factors found for the shot- 
gun soundings and the first and second periods of the 
sonic depth finder are attributed to the changing rate of 
the stop watch. Viewed in this light it is to be noted that 



when these three timing factors are plotted against time 
they fall practically on a straight line. Such a plot is 
shown in figure 2, in which the date of the first adjust- 
ment of the depth finder is taken as May 28, 1928; the 
date of the shotgun ratio is taken as the mean date of the 
comparisons on which it is based, December 19, 1928; 
and the date of the second adjustment of the depth finder 
is taken as February 19, 1929. 

These timing factors place the shotgun soundings 
and the sonic depth finder soundings all on a common 
basis, which is referred to the unprotected deep-sea re- 
versing thermometers for a standard of depth. 



CORRECTIONS OF SONIC DEPTHS ON ACCOUNT OF ERRORS IN TIMING 



59 



Table 4. Comparison between shotgun soundings and soundings by wire or 
unprotected thermometers 



Station 


Depths in meters 


Ratios 


no. 


Wire 


Ther- 
mometer 


Shotgun 


Wire to 
shotgun 


Thermometer 
to shotgun 



43 


3352 




3716 


0.902 


46 


2905 


2840 


2999 


0.969 


47 


3080 




2999 


1.027 


49 


3028 




3187 


0.950 


51 


3063 


2898 


3180 


0.963 


52 


2801 


2851 


2899 


0.966 


54 


3063 




3147 


0.973 


56 


3135 




3409 


0.920 


57 


3139 




3294 


0.953 


59 


4116 




4355 


0.945 


60 


4007 




4087 


0.980 


61 


3299 




3518 


0.938 


62 


3610 




3823 


0.944 


63 


3393 




3446 


0.985 


64 


3820 


3879 


3880 


0.985 


65 


3580 


3626 


3659 


0.978 


67 


1085 


1089 


1278 a 




68 
68 


41461- 
4166J 




4309 


0.964 


69 


3657 




3845 


0.951 


70 


4739 




5054 


0.938 



0.947 



0.911 
0.983 



1.000 
0.991 



Average 



0.960 ±0.006 



a Merriam Ridge 

Note . --Omitting station 67, we have the following average ratios of depths: wire to 
shotgun, 0.958; wire and thermometer where available, to shotgun, 0.957; thermometer 
to shotgun, 0.969; wire to shotgun at stations where thermometer depths are available, 
0.973. 



- 


1 1 
os 


i 


i 


1 


1 


> 


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L fe! °> 








- 




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- 


5S 


2 


^ [ # ---^^ 




\^ 






Q 














^. 








\ t 


k 


7- 


5 

k 


■» 










/ 


O 
k 








U. 1 
S \ 

8i \ 




/ 


ft 

h 




























5 

"5 

Uj 












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1 


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> c 

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fe 8 s 
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Ju 5 5 ^ k 
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INUS DEPTH f. 


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k k £ O 

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60 






SOUNDING VELOCITY 



By sounding velocity is meant the average velocity 
of sound over a vertical path from the sea surface to the 
depth in question. As the sounding velocity is dependent 
on the actual velocity at intervals along the vertical path 
and as the actual velocity is a function of the tempera- 
ture, salinity, and pressure, a knowledge of the vertical 
distribution of temperature and salinity is necessary be- 
fore the sounding velocity at any point can be computed. 
The vertical distribution of temperature and salinity was 
determined from actual measurements at each oceano- 
graphic station (that is, about every other day) down to 
depths which were usually from 2000 to 4000 meters. 
The deep-water observations indicated that certain of 
the oceanographic stations had vertical temperature and 
salinity distributions sufficiently similar to be grouped 
together. Accordingly, all measured values below 2000 
meters for a given group of stations were plotted on a 
single graph which was used for extrapolating the indi- 
vidual temperature and salinity curves for stations with- 
in that group. Scaled values of temperature and salinity 
for the nominal depth intervals down to 2500 meters are 
given for each oceanographic station in table 2 (see 
Oceanography I-B). Extrapolated values for depths be- 
low 2500 meters as determined by groups are shown in 
table 1. Wherever the vertical distribution curves based 
on actual measurements extend below 2500 meters, 
values scaled from these curves have been used instead 
of the values obtained from group extrapolation. The 
sounding velocities computed from the conditions found 
to exist at the oceanographic stations are given in table 
5 (Oceanography I-B). In this table the values appearing 
below the heavy line are based on extrapolated tempera- 
tures or salinities. The sounding velocities given are 
probably significant to a few tenths of a meter per sec- 
ond as representing the conditions at the time measure- 
ments were made, but must not be relied on as repre- 
senting the conditions at any other time. 

There are seasonal variations in both temperature 
and salinity in the upper layers. Of these, the variations 
in temperature have the greater effect on sound velocity. 
In general, the temperate regions suffer the greatest 
annual variations in surface temperature, whereas the 
tropics and polar regions have smaller changes. Sur- 
face temperatures may vary as much as 10° C in the 
temperate regions and even more in the vicinity of the 
boundaries of pronounced streams such as the Japan 
Current and the Gulf Stream. Little is known regarding 
subsurface variations in temperature in the open ocean. 
It seems reasonable, however, to expect that annual 
variations occur to depths as great as those at which the 
rapid temperature decrease of the thermocline changes 
to the gradual temperature decrease at greater depths. 
Let us assume, then, that significant annual variations 
in temperature occur down to 500 meters and that the 
temperature at the surface may be 10° C different from 
the values measured on the Carnegie . Under such con- 
ditions the values of sounding velocity given in table 5 
(Oceanography I-B) would be in error by about 0.2 per 
cent at a depth of 2500 meters and the error at 4000 
meters would be about 2 meters per second. 

Vertical sections showing the sounding velocity 
along the path of the Carnegie have been prepared from 
the computed values given in table 5 (Oceanography I-B). 



These sections are approximately south-north and west- 
east, but the abscissas represent great circle distances 
between oceanographic stations. In order to show the 
variations, the vertical distances are shown on a scale 
which magnifies them 1000 times with respect to the 
horizontal scale. It is believed that sounding velocities 
shown in these sections, particularly in the Pacific, can 
be used to reduce future soundings in depths greater 
than 2500 meters not in the vicinity of pronounced 
streams with an error of less than one-fifth per cent in 
the sounding velocity. A horizontal section showing the 
sounding velocity at a level of 4000 meters (fig. 1) is 
given for the Pacific. An inspection of this indicates 
that the sounding velocities represented by the vertical 
sections can be applied to areas adjacent to the actual 
sections as follows: sections IV, VIII, X, XI, XII, and 
XIII apply 200 miles on each side; sections III, V, VI, 
XV, and XVI apply 100 miles on each side; sections VII, 
IX, and XIV apply 50 miles on each side. 

In the British Admiralty Hydrographic Department 
Publication No. 282 entitled "Tables of the velocity of 
sound in pure water and sea-water for use in echo- 
sounding and sound -ranging" the oceans are divided 
into twenty-three areas within which echo soundings may 
be roughly reduced by means of appropriate tables of 
sounding velocity. The boundaries between these areas 
were intersected a number of times by the path of the 
Carnegie and the accompanying vertical sections conse- 
quently represent additional data on which to base the 
location of these boundaries. The boundary conditions 
were assumed to be the means of the sounding velocities 
given in the British Admiralty tables as applicable, at 
given depths, to the two adjacent areas. These boundary 
conditions were then located on the vertical sections, 
more attention being paid to the deeper layers than to 
the layers above the minimum. The boundary locations, 
as indicated by the Carnegie sections, are shown by 
broken lines superimposed on a chart giving the British 
Admiralty boundaries. This is shown in figures 2 and 3. 
The boundary between areas 17 and 5 is shifted some- 
what to the south. Boundary 6 to 3 could not be very 
well located and has been omitted. Boundary 3 to 10 is 
shifted nearly 5° to the north. In the Pacific, boundary 

18 to 20 seems to be south of the south end of Section III 
and east of the east end of Section X. Boundary 16 to 
18, off the South American coast, is also shifted to the 
south. The eastern tip of boundary 16 to 13 is shifted 
westward thr.ough about 20° of longitude. Boundary 9 to 
13 is apparently south and west of the Samoan Islands. 
The southern boundary of area 15 is shifted south and 
its northern boundary is shifted north. Boundary 13 to 
16, north of Guam, is shifted south. Boundary 16 to 18, 
off the Japanese coast, is practically the same, and 
boundary 18 to 19 in this vicinity is the same. Boundary 

19 to 21, however, is shifted considerably south, being 
south of the entire Section XVI. In view of this it seems 
probable that the northward bulge of boundary 18 to 19 
is not so pronounced. The eastern end of boundary 18 to 
19 is shifted but slightly to the south. Boundary 16 to 18 
has an irregularity introduced northeast of the Hawaiian 
Islands. The boundary between areas 13 and 16, south- 
east of the Hawaiian Islands, could not be very well lo- 
cated on Section V. It seems probable that the values of 



61 



62 



OBSERVATIONS AND RESULTS IN PHYSICAL OCEANOGRAPHY 

















Table 1. Group extrapolation 






Depth 


3, 4, 5, 6, 
10, and 11 


12 


14 


2 and 15 


16 to 19 




Temp. 


Salin. 


Temp. 


Salin. 


Temp. 


Salin. 


Temp. 


Salin. 


Temp. 


Salin. 



m 


°C 


%o 


°C 


%0 


°C 


o/oo 


°C 


o/oo 


°C 


o/oo 


3000 


2.90 


34.91 


2.35 


34.91 


2.90 


34.90 


3.15 


34.92 


2.80 


34.90 


3500 


2.80 


34.90 


2.30 


34.90 


2.55 


34.89 


2.80 


34.91 


2.65 


34.89 


4000 


2.70 


34.90 






2.25 


34.89 


2.50 


34.90 


2.60 


34.88 


4500 


2.60 


34.89 






2.20 


34.88 


2.40 


34.88 


2.50 


34.87 


5000 


2.50 


34.89 










2.35 


34.85 


2.45 


34.85 


5500 


2.45 


34.88 










2.25 


34.83 


2.40 


34.83 


6000 














2.20 


34.82 


2.35 


34.82 


6500 























Depth 



58 to 62 



63 to 67 



47 and 
68 to 79 



80 to 92 



93 to 94 and 
160 to 162 



3000 


1.75 


34.69 


1.75 


34.66 


1.80 


34.68 


1.70 


34.66 


1.70 


34.66 


3500 


1.35 


34.69 


1.70 


34.66 


1.80 


34.68 


1.60 


34.67 


1.60 


34.67 


4000 


1.10 


34.69 


1.70 


34.67 


1.80 


34.68 


1.45 


34.67 


1.40 


34.67 


4500 


1.10 


34.69 


1.70 


34.67 


1.80 


34.68 


1.35 


34.67 


1.10 


34.67 


5000 


1.10 


34.68 


1.70 


34.67 


1.80 


34.68 


1.30 


34.67 


1.10 


34.67 


5500 










1.80 


34.68 


1.20 


34.67 


1.10 


34.67 


6000 










1.80 


34.68 


1.15 


34.67 


1.10 


34.67 


6500 














1.15 


34.67 






7000 






















7500 






















8000 






















8500 






















9000 























(Salinity values probably 0.03 o/oo too low; see page 72) 



sounding velocity for either area 13 or 16 should be 
revised. The shifted boundaries are shown by broken 
lines of appreciable length, although only a single point 
is located at each crossing. To show these single points 
more definitely, lines have been drawn connecting the 
two oceanographic stations nearest each of these points 
of intersection. 

As shown in one of the preceding sections (pp. 50-53). 
correction had to be applied to the sonic depths, owing 
to error in the timing, by multiplying the computed 
depths from various parts of the cruise by a constant 
factor. This has been done and the final values, togeth- 
er with their positions, are given in table 4 (Oceanogra- 
phy I -B). 



It is believed that, except where otherwise noted in 
this table, the soundings are accurate within the follow- 
ing limits: soundings to 360 inclusive, +1.0 per cent; 
soundings 361 to 476 inclusive, +1.5 per cent; soundings 
477 to 534 inclusive, +1.0 per cent; and soundings 535 
to 1496 inclusive, +0.5 per cent. 

The sonic soundings listed in table 4 (Oceanography 
I-B) are nearly all shown graphically in twenty-eight 
bottom profiles, of which twelve have been plotted 
against latitude and sixteen have been plotted against 
longitude. The course followed by the Carnegie has 
been shown on each profile. 



SOUNDING VELOCITY 



63 



of temperature and salinity 



Station number 



20 to 30 


31 to 34 


35 to 38 


3£ to 45 


46 and 

48 to 50 


51 to 57 


Temp. 


Salin. 


Temp. 


Salin. 


Temp. 


Salin. 


Temp. 


Salin. 


Temp. 


Salin. 


Temp. 


Salin. 



°C 


%o 


°C 


°/oo 


°C 


o/oo 


°C 


o/oo 


°C 


o/oo 


°C 


o/oo 


2.80 


34.91 


4.05 


34.72 


2.05 


34.63 


1.70 


34.66 


1.90 


34.66 


1.80 


34.66 


2.60 


34.90 


4.05 


34.72 


2.15 


34.63 


1.65 


34.67 


1.85 


34.67 


1.75 


34.67 


2.45 


34.89 


4.05 


34.72 


2.25 


34.63 


1.60 


34.67 


1.80 


34.67 


1.70 


34.67 


2.30 


34.87 


4.05 


34.72 


2.30 


34.63 


1.55 


34.67 










2.20 


34.85 


4.05 


34.72 


2.40 


34.63 


1.55 


34.67 










2.10 


34.83 


4.05 


34.72 


















2.00 


34.82 






















1.90 


34.81 























95 to 100 



101 to 108 



109 to 129 



130 to 149 



150 



151 to 159 



1.70 


34.64 


1.65 


34.64 


1.60 


34.64 


1.60 


34.64 


1.65 


34.65 


1.75 


34.65 


1.65 


34.65 


1.60 


34.65 


1.55 


34.64 


1.50 


34.64 


1.55 


34.66 


1.55 


34.66 


1.60 


34.65 


1.60 


34.65 


1.55 


34.64 


1.55 


34.65 


1.40 


34.65 


1.40 


34.65 


1.60 


34.65 


1.55 


34.65 


1.55 


34.64 


1.55 


34.65 


1.40 


34.64 


1.40 


34.64 


1.55 


34.66 


1.55 


34.66 


1.55 


34.64 


1.50 


34.65 


1.50 


34.64 


1.50 


34.64 


1.55 


34.66 


1.55 


34.66 


1.55 


34.64 


1.60 


34.65 


1.35 


34.64 


1.35 


34.64 


1.60 


34.66 


1.60 


34.66 


1.60 


34.64 


1.65 


34.65 


1.20 


34.64 


1.20 


34.64 


1.70 


34.67 


1.70 
1.75 
1.85 
1.90 
2.00 


34.67 
34.67 
34.67 
34.67 
34.67 


1.70 
1.75 
1.85 
1.90 
2.00 
2.05 


34.64 
34.64 
34.64 
34.64 
34.64 
34.64 


1.70 


34.65 






1.10 


34.64 




o 
o 



o 

:z 

Q 

Z 

O 

CO 

O 



Q 



64 



DETERMINATION OF SALINITY 



The salinities were measured by the conductivity 
method using a Wenner salinity bridge (Wenner, Smith, 
and Soule, 1930). This instrument was of the type de- 
signed by Dr. Frank Wenner, of the Bureau of Standards, 
originally for the International Ice Patrol Service. It 
consists essentially of an alternating current Wheat- 
stone's bridge, two adjacent arms of the bridge being 
formed by two similar electrolytic cells, the other two 
arms being made up of two fixed coils of manganin wire 
between which is a slide wire. The electrolytic cells 
are immersed in a stirred water bath which is thermo- 
statically controlled at constant temperature. A sub- 
stitution method is employed so that cell constants and 
absolute conductivities need not be known. Sea water, 
the salinity of which is unimportant within limits, is 
placed in one of the cells and sea water of known salinity 
is placed in the other cell. A small resistance in series 
with the first cell is then adjusted until the bridge is 
balanced when the slide-wire reading corresponds to the 
salinity of the known sample. This sample is then with- 
drawn and replaced by the unknown sample which is to 
be measured. The bridge is balanced this time by the 
adjustment of the slide wire, thus giving the conductivity 
of the unknown in terms of the known. The conductivi- 
ties may be converted into salinities, but it is custom- 
ary to calibrate the instrument by the measurement of a 
number of samples of known salinity so that the slide- 
wire reading may be converted directly into salinity 
without a knowledge of the relation between salinity and 
conductivity. 

It can be assumed that the relation between salinity 
and conductivity is linear, but not proportional, over the 
range encountered in sea water. On this assumption the 
relation between slide -wire readings and salinity in an 
instrument of this sort can be expressed by an equation 
of the type 

S=S' [1 + A(s-s') +B(s-s') 2 +C(s-s') 3 -...] (1) 

in which s is the slide-wire reading corresponding to 
any salinity S," and s' is the slide-wire reading corre- 
sponding to the salinity S', 'and A, B, C, .... are numeri- 
cal constants depending on s', S', the relation between 
salinity and conductivity, and the constants of the bridge 
circuit. The numerical limits of the salinity range of 
such an instrument are fixed by the ratio of the resist- 
ance of one division of the slide wire to the resistance 
of the two bridge arms which include the slide wire, and 
by the arbitrary selection of the slide-wire reading s' 
which will correspond to the salinity S'. In the Carnegie 
instrument the slide wire had 1000 divisions, each of 
which had a resistance of 1/15,000 of the sum of the re- 
sistances of the two adjacent bridge arms which includ- 
ed the slide wire. Under these conditions, terms in 
equation (1) involving (s - s') to exponents greater than 
3 are negligibly small and the third-degree term need 
only be considered when (s - s') is numerically large. 
When s' is selected near the middle of the slide wire, 
the second-degree equation can be used with negligible 
error. 

In the case of this instrument a slide-wire reading 
s' of 699.5 was selected as corresponding to a salinity 
S' of 35.00 per mille, so that a second-degree equation 
can be used to express the calibration curve. If any 



irregularities existed in the slide wire the calibration 
curve would have had departures from the curve of such 
an equation since the development of the equation as- 
sumes direct proportionality between slide-wire reading 
and slide-wire resistance. 

Time did not permit of a test being made for uni- 
formity of the slide wire before the departure of the 
Carnegie in May 1928. The preliminary calibration of 
the bridge was therefore made in the following manner. 
Standard water from the International Bureau at Copen- 
hagen having a salinity of 34.99 per mille was placed in 
the test cells and the bridge was balanced with the slide 
wire set at a reading of 698.5. The slide-wire readings 
at balance were then determined for five other samples 
of known salinity furnished by the Scripps Institution of 
Oceanography, and titrated against Copenhagen standard 
water by H. R. Seiwell. A curve was then drawn through 
these six well-distributed points*. From time to time, 
as the cruise progressed, some of the samples which 
were measured in the bridge were also titrated against 
standard water in a Knudsen burette by the silver nitrate 
method. Each of these samples furnished an additional 
point on the calibration curve. All such points ultimate- 
ly obtained are shown in figure 1. The origin of these 
samples and the comparison values are given in table 1. 

Because of the considerable range of room tempera- 
ture encountered in a cruise such as that of the Carnegie , 
two regulating temperatures were provided for. In colder 
weather the water bath was regulated at a temperature of 
about 30° C and in the tropics a temperature of about 40° 
C was used. In the hope that the slope and curvature of 
the calibration curve at 40° C would be practically the 
same as for 30° C, the same arbitrary point, namely, 
salinity 34.99 per mille at slide-wire reading 698.5, was 
selected for each temperature. The points determined 
at a regulating temperature of 30° C are shown in figure 
1 by circles and those determined at 40° C by crosses. 
The arbitrarily selected point is shown as a solid circle 
and cross. As there were no systematic differences be- 
tween the points determined at the two temperatures, all 
points could be used in determining the calibration curve. 
This meant further that the exact temperature of regula- 
tion was unimportant as long as it did not change materi- 
ally during a series of measurements. 

Figure 1 includes all comparisons made on the Car - 
negie between bridge and titration methods. None was 
discarded. It includes all differences arising from both 
instrumental and observational error in both bridge and 
titration measurements, as well as any differences aris- 
ing from variation in salt ratios in samples from differ- 
ent localities. As an individual bridge measurement is 
accurate to about 0.01 to 0.02 per mille salinity, and as 
an individual titration is subject to a similar error, it 
was expected that the points would scatter over from 
0.02 to 0.04 per mille on each side of a smooth curve. 

The second-degree equation whose curve fits the 
points shown in figure 1 is 

S = 35 [1 + 295.7 x 10" 6 (s - 699.5) 

+ 46. x lO" 9 (s - 699.5)2] (2) 

The slide-wire readings of all the points shown in figure 
1 were converted into salinities by this equation and 
their differences from the titration values plotted against 



67 



68 



OBSERVATIONS AND RESULTS IN PHYSICAL OCEANOGRAPHY 



Table 1. Titration comparisons used in calibration of salinity bridge 



Date 



Bridge 



Titration 



Sta- 
tion 
no. 



Latitude 



Longitude 



Depth 



Salinity 

by 
titration 



Slide - 

wire 

reading 



Nominal 

regulating 

temperature 



1928 


1928 




O / 


° / 


m 


%o 




°C 


July 15 
15 




8 

8 

8 

11 


63 30.1 N 
63 30.1 N 
63 30.1 N 
58 12.1 N 


14 40.7 W 
14 40.7 W 
14 40.7 W 
35 51.4 W 




300 

1000 

581 


35.23 
35.26- 
35.09 
34.93 


720.6 
722.6 
708.5 
692.2 


30 




30 


15 




30 


Aug. 1 


Aug. 7 


30 


5 


7 


12 


51 39.8 N 


49 31.7 W 


435 


34.82 


685.6 


30 


16 




Prepared sample 
Prepared sample 




33.48 
36.20 


547.6 
809.5 


40 


16 




40 


Oct. 8 


Oct. 9 


33 


13 37.2 N 


76 22.5 W 


661 


34.74 


674.8 


40 


26 


27 


35 


6 32.5 N 


80 04.1 W 


27 


33.50 


554.7 


40 


Nov. 3 




38 
38 
38 
41 


3 45.8 N 
3 45.8 N 
3 45.8 N 
1 36.6 S 


81 36.8 W 
81 36.8 W 
81 36.8 W 
86 58.2 W 




47 

516 

6 


32.86 
34.20 
34.60 
34.19 


488.0 
624.1 
662.5 
621.0 


40 


3 




40 


3 




40 


10 


Nov. 10 


30 


10 


10 


41 


1 36.6 S 


86 58.2 W 


23 


34.53 


653.6 


30 


10 


10 


41 


1 36.6 S 


86 58.2 W 


323 


34.83 


682.3 


30 


13 


14 


42 


1 32.2 S 


93 09.7 W 





34.70 


672.6 


30 


13 


14 


42 


1.32.2 S 


93 09.7 W 


578 


34.59 


661.7 


30 


13 


14 


Evaporimeter sample 




34.41 


642.0 


30 


19 


19 


45 


4 35.1 S 


105 03.4 W 


238 


34.87 


689.1 


30 


19 


19 


45 


4 35.1 S 


105 03.4 W 


310 


34.86 + 


684.8 


30 


19 


19 


45 


4 35.1 S 


105 03.4 W 


1176 


34.60- 


685.1 


30 


21 


22 


46 


9 06.3 S 


108 19.6 W 


6 


35.35 


728.0 


30 


21 


22 


46 


9 06.3 S 


108 19.6 W 


74 


35.37 


733.0 


30 


21 


22 


46 


9 06.3 S 


108 19.6 W 


146 


35.43 


737.4 


30 


23 


24 


47 


14 07.4 S 


111 50.4 W 





35.99- 


787.3 


30 


23 


24 


47 


14 07.4 S 


111 50.4 W 


5 


35.99+ 


785.2 


30 


23 


24 


47 


14 07.4 S 


111 50.4 W 


53 


35.95 


789.6 


30 


23 


24 


47 


14 07.4 S 


111 50.4 W 


77 


36.06- 


795.3 


30 


23 


24 


41 


14 07.4 S 


111 50.4 W 


95 


36.15 


805.6 


30 


23 


24 


47 


14 07.4 S 


111 50.4 W 


205 


35.70+ 


764.4 


30 


23 


24 


47 


14 07.4 S 


111 50.4 W 


314 


34.54- 


657.8 


30 


23 


24 


47 


14 07.4 S 


111 50.4 W 


425 


34.62+ 


660.3 


30 


23 


24 


47 


14 07.4 S 


111 50.4 W 


2044 


34.63+ 


664.0 


30 


Dec. 5 


Dec. 6 


53 


29 06.5 S 


108 44.4 W 


4 


35.67 


762.3 


30 ' 


5 


6 


53 


29 06.5 S 


108 44.4 W 


44 


35.765 


769.2 


30 


5 


6 


53 


29 06.5 S 


108 44.4 W 


174 


35.12+ 


713.6 


30 


5 


6 


53 


29 06.5 S 


108 44.4 W 


309 


34.75- 


678.5 


30 


5 


6 


53 


29 06.5 S 


108 44.4 W 


360 


34.55- 


655.2 


30 


5 


6 


53 


29 06.5 S 


108 44.4 W 


543 


34.32 


635.2 


30 


5 


6 


53 


29 06.5 S 


108 44.4 W 


794 


34.28 


631.0 


30 


5 


6 


53 


29 06.5 S 


108 44.4 W 


1238 


34.44- 


649.1 


30 


5 


6 


Evaporimeter sample 




35.70 


766.0 


30 


26 


26 


Evaporimeter sample 


- 


37.68 


948.6 


30 


26 


26 


Evaporimeter s 


ample 




37.23 


906.0 


30 


26 


26 


60 


40 23.9 S 


97 32.7 W 





33.93- 


594.2 


30 


26 


26 


60 


40 23.9 S 


97 32.7 W 


70 


33.99 


605.2 


30 


26 


26 


60 


40 28.9 S 


97 32.7 W 


92 


33.97 


603.5 


30 


26 


26 


60 


40 23.9 S 


97 32.7 W 


185 


34.11 


618.0 


30 


26 


26 


60 


40 23.9 S 


97 32.7 W 


712 


34.22 


625.7 


30 


26 


26 


60 


40 23.9 S 


97 32.7 W 


2600 


34.63+ 


666.2 


30 


1929 


1929 
















Jan. 7 


Jan. 8 


66 


27 04.4 S 


84 01.1 W 


6 


34.70 


670.2 


30 


7 


8 


66 


27 04.4 S 


84 01.1 W 


48 


34.79 


680.0 


30 


7 


8 


66 


27 04.4 S 


84 01.1 W 


96 


34.94 


694.9 


30 


7 


8 


66 


27 04.4 S 


84 01.1 W 


193 


34.50 


653.8 


30 


7 


8 


66 


27 04.4 S 


84 01.1 W 


293 


34.41 


645.4 


30 


7 


8 


66 


27 04.4 S 


84 01.1 W 


391 


34.45 


647.2 


30 


7 


8 


66 


27 04.4 S 


84 01.1 W 


751 


34.37 


639.9 


30 


7 


8 


66 


27 04.4 S 


84 01. IW 


1617 


34.57 


658.2 


30 


7 


8 


66 


27 04.4 S 


84.01.1 W 


2606 


34.63 


666.8 


30 


7 


8 


Evaporimeter sample 




37.59 


939.8 


30 


Feb. 18 


Feb. 18 


77 


14 20.0 S 


103 12.5 W 





36.04 


794.5 


30 


18 


18 


77 


14 20.0 S 


103 12.5 W 


69 


36.02 


793.1 


30 


18 


18 


77 


14 20.0 S 


103 12.5 W 


92 


35.97 


791.0 


30 


18 


18 


77 


14 20.0 S 


103 12.5 W 


182 


35.43 


736.8 


30 


18 


18 


77 


14 20.0 S 


103 12.5 W 


2721 


34.65 


668.8 


30 


24 


25 


80 


12 39.0 S 


117 22.1 W 


5 


35.91 


785.1 


30 


24 


25 


80 


12 39.0 S 


117 22.1 W 


22 


35.91 


787.1 


30 


24 


25 


80 


12 39.0 S 


117 22.1 W 


44 


35.92 


786.3 


30 


24 


25 


80 


12 39.0 S 


117 22.1 W 


66 


36.04 


795.7 


30 


24 


25 


80 


12 39.0 S 


117 22.1 W 


88 


36.19 


812.6 


30 


24 


25 


80 


12 39.0 S 


117 22.1 W 


133 


36.31- 


820.6 


30 


24 


25 


80 


12 39.0 S 


117 22.1 W 


180 


35.82+ 


778.6 


30 


24 


25 


80 


12 39.0 S 


117 22.1 W 


226 


35.17 


719.1 


30 


24 


25 


80 


12 39.0 S 


117 22.1 W 


840 









DETERMINATION OF SALINITY 



69 





Table 1. 


Titration comparisons used in calibration of salinity bridge—Continued 


Date 


Sta- 








Salinity 


Slide- 


Nominal 






tion 


Latitude 


Longitude 


Depth 


by 


wire 


regulating 


Bridge 


Titration 


no. 








titration 


reading 


temperature 


*929 


1929 




o / 


O / 


m 


o/oo 




°C 


Feb. 24 


Feb. 25 


80 


12 39.0 S 


117 22.1 W 


840 


34.45 


650.3 


30 


24 


25 


Evaporimeter sample 




36.02 


793.5 


30 


Mar. 2 


Mar. 3 


Evaporimeter sample 




36.33 


828.4 


30 


2 


3 


83 


17 00.4 S 


129 45.0 W 


49 


36.50 


842.0 


30 


2 


3 


83 


17 00.4 S 


129 45.0 W 


73 


36.41 


835.5 


30 


2 


3 


83 


17 00.4 S 


129 45.0 W 


98 


36.26 


820.0 


30 


2 


3 


83 


17 00.4 S 


129.45.0 W 


146 


36.28 


823.9 


30 


2 


3 


83 


17 00.4 S 


129 45.0 W 


244 


35.52 


751.9 


30 


2 


3 


83 


17 00.4 S 


129 45.0 W 


645 


34.39 


644.2 


30 


4 


5 


84 


17 11.4 S 


133 17.6 W 





36.24 


814.8 


30 


4 


5 


84 


17 11.4 S 


133 17.6 W 


23 


36.35 


826.7 


30 


4 


5 


84 


17 11.4 S 


133 17.6 W 


71 


36.43+ 


835.2 


30 


4 


5 


84 


17 11.4 S 


133 17.6 W 


190 


36.17+ 


810.2 


30 


4 


5 


84 


17 11.4 S 


133 17.6 W 


333 


34.73 


676.9 


30 


27 


28 


91 


15 44.3 S 


160 25.3 W 





35.15 


712.0 


40 


27 


28 


91 


15 44.3 S 


160 25.3 W 


20 


35.17 


714.5 


40 


27 


28 


91 


15 44.3 S 


160 25.3 W 


66 


35.79 


769.7 


40 


27 


28 


91 


15 44.3 S 


160 25.3 W 


86 


35.91 


783.7 


40 


27 


28 


91 


15 44.3 S 


160 25.3 W 


173 


36.03 


791.6 


40 


27 


28 


91 


15 44.3 S 


160 25.3 W 


261 


35.61 


754.5 


40 


27 


28 


91 


15 44.3 S 


160 25.3 W 


615 


34.41 


641.4 


40 


27 


28 


91 


15 44.3 S 


160 25.3 W 


927 


34.50 


652.6 


40 


27 


28 


91 


15 44.3 S 


160 25.3 W 


2269 


34.62 


660.8 


40 


27 


28 


91 


15 44.3 S 


160 25.3 W 


2701 


34.44 


649.7 


40 


27 


28 


91 


15 44.3 S 


160 25;3 W 


3863 


34.67 


666.8 


40 


May 9 


May 10 


102 


16 24.9 N 


171 59.3 E 


84 


34.99 


699.8 


40 


9 


10 


102 


16 24.9 N 


171 59.3 E 


126 


35.08 


707.0 


40 


9 


10 


102 


16 24.9 N 


171 59.3 E 


170 


35.23 


721.7 


40 


9 


10 


102 


16 24.9 N 


171 59.3 E 


255 


34.94 


696.9 


40 


9 


10 


102 


16 24.9 N 


171 59.3 E 


338 


34.33 


636.9 


40 


9 


10 


102 


16 24.9 N 


171 59.3 E 


423 


34.20 


624.8 


40 


9 


10 


102 


16 24.9 N 


171 59.3 E 


987 


34.49 


651.0 


40 


9 


10 


102 


16 24.9 N 


171 59.3 E 


2655 


34.65 


665.6 


40 


15 


16 


105 


18 42.8 N 


156 15.8 E 





34.92 


692.8 


40 


15 


16 


105 


18 42.8 N 


156 15.8 E 


70 


35.04 


701.8 


40 


15 


16 


105 


18 42.8 N 


156 15.8 E 


93 


35.12 


710.7 


40 


15 


16 


105 


18 42.8 N 


156 15.8 E 


188 


35.15 


714.2 


40 


15 


16 


105 


18 42.8 N 


156 15.8 E 


235 


34.90 


690.5 


40 


15 


16 


105 


18 42.8 N 


156 15.8 E 


437 


34.32 


634.8 


40 


15 


16 


105 


18 42.8 N 


156 15.8 E 


893 


34.38 


640.6 


40 


15 


16 


105 


18 42.8 N 


156 15.8 E 


1693 


34.57 


660.4 


40 


27 


28 


108 


18 26.1 N 


144 01.2 E 


23 


34.99 


696.9 


40 


27 


28 


108 


18 26.1 N 


144 01.2 E 


281 


34.79+ 


679.7 


40 


27 


28 


108 


18 26. IN 


144 01.2 E 


377 


34.53 


655.1 


40 


27 


28 


108 


18 26.1 N 


144 01.2 E 


649 


34.25 


629.1 


40 


27 


28 


108 


18 26.1 N 


144 01.2 E 


1412 


34.55 


657.8 


40 


27 


28 


108 


18 26.1 N 


144 01.2 E 


2335 


34.64- 


663.9 


40 


June 3 


June 4 


111 


31 00.1 N 


144 16.2 E 


71 


34.70 


668.2 


40 


3 


4 


111 


31 00.1 N 


144 16.2 E 


187 


34.74 


673.6 


40 


3 


4 


111 


31 00.1 N 


144 16.2 E 


377 


34.44 


644.3 


40 


3 


4 


111 


31 00.1 N 


144 16.2 E 


471 


34.15 


617.2 


.40 


3 


4 


111 


31 00.1 N 


144 16.2 E 


483 


34.14 


618.0 


40 


3 


4 


111 


31 00.1 N 


144 16.2 E 


559 


34.08 


611.5 


40 


3 


4 


111 


31 00.1 N 


144 16.2 E 


565 


33.97 


601.4 


40 


July 1 


July 2 


116 


38.40.9 N 


147 41.2 E 





33.99 


606.3 


30 




2 


116 


38 40.9 N 


147 41.2 E 


22 


33.96 


603.5 


30 




2 


116 


38 40.9 N 


147 41.2 E 


43 


33.77 


581.7 


30 




2 


116 


38 40.9 N 


147 41.2 E 


65 


34.03 


609.0 


30 




2 


116 


38 40.9 N 


147 41.2 E 


444 


34.10 


613.0 


30 




2 


116 


38 40.9 N 


147 41.2 E 


535 


34.18 


621.4 


30 




2 


116 


38 40.9 N 


147 41.2 E 


668 


34.24 


628.4 


30 




2 


116 


38 40.9 N 


147 41.2 E 


781 


34.31 


633.1 


30 




8 


119 


45 24.0 N 


159 35.7 E 





32.99 


495.8 


30 




8 


119 


45 24.0 N 


159 35.7 E 


5 


33.01 


497.5 


30 




8 


119 


45 24.0 N 


159 35.7 E 


22 


33.02 


501.4 


30 




8 


119 


45 24.0 N 


159 35.7 E 


45 


33.06 


503.7 


30 




8 


119 


45 24.0 N 


159 35.7 E 


72 


33.14 


514.6 


30 




8 


119 


45 24.0 N 


159 35.7 E 


90 


33.12 


512.8 


30 


7 


8 


119 


45 24.0 N 


159 35.7 E 


97 


33.20 


520.7 


30 


7 


8 


119 


45 24.0 N 


159 35.7 E 


183 


33.77 


576.1 


30 


7 


8 


119 


45 24.0 N 


159 35.7 E 


230 


33.93 


592.2 


30 


7 


8 


119 


45 24.0 N 


159 35.7 E 


277 


34.02 


601.9 


30 


13 


14 


122 


46 16.3 N 


174 03.0 E 





32.81 


483.3 


30 


13 


14 


122 


46 16.3 N 


174 03.0 E 


22 


32.87 


487.3 


30 



70 OBSERVATIONS AND RESULTS IN PHYSICAL OCEANOGRAPHY 

Table 1. Titration comparisons used in calibration of salinity bridge --Concluded 



Date 


Sta- 








Salinity 


Slide- 


Nominal 






tion 


Latitude 


Longitude 


Depth 


by 


wire 


regulating 


Bridge 


Titration 


no. 








titration 


reading 


temperature 


1929 


1929 




o 


o 


m 






°C 


July 13 


July 14 


122 


46 16.3 N 


174 03.0 E 


45 


33.04 


505.3 


30 


13 


14 


122 


46 16.3 N 


174 03.0 E 


67 


33.09 


509.6 


30 


13 


14 


122 


46 16.3 N 


174 03.0 E 


90 


33.12 


512.0 


30 


13 


14 


122 


46 16.3 N 


174 03.0 E 


135 


33.21 


519.2 


30 


13 


14 


122 


46 16.3 N 


174 03.0 E 


182 


33.41 


543.5 


30 


13 


14 


122 


46 16.3 N 


174 03.0 E 


273 


33.79 


581.9 


30 


13 


14 


122 


46 16.3 N 


174 03.0 E 


365 


33.98 


602.3 


30 


13 


14 


122 


46 16.3 N 


174 03.0 E 


460 


34.12 


614.0 


30 


19 


20 


125 


53 57.7 N 


150 38.7 W 





32.75- 


474.5 


30 


19 


20 


125 


51 57.7 N 


150 38.7 W 


5 


32.74+ 


473.4 


30 


19 


20 


125 


51 57.7 N 


150 38.7 W 


24 


32.73 


471.8 


30 


19 


20 


125 


51 57.7 N 


150 38.7 W 


46 


32.79 


478.6 


30 


19 


20 


125 


51 57.7 N 


150 38.7 W 


66 


32.84 


481.6 


30 


19 


20 


125 


51 57.7 N 


150 38.7 W 


175 


33.85 


583.9 


30 


25 


26 


128 


10 36.8 N 


132 23.3 W 


1093 


34.41 


645.7 


30 


25 


26 


128 


40 36.8 N 


132 23.3 W 


1655 


34.47 


651.2 


30 


25 


26 


128 


40 36.8 N 


132 23.3 W 


2180 


34.60 


658:9 


30 


Sep. 10 


Sep. 11 


133 


29 20.7 N 


132 30.0 W 





34.71 


671.6 


30 


10 


11 


133 


29 20.7 N 


132 30.0 W 


23 


34.73 


680.9 


30 


10 


11 


133 


29 20.7 N 


132 30.0 W 


93 


34.77 


678.2 


30 


10 


11 


133 


29 20.7 N 


132 30.0 W 


279 


33.96 


597.7 


30 


10 


11 


133 


29 20.7 N 


132 30.0 W 


373 


33.98 


607.1 


30 


10 


11 


133 


29 20.7 N 


132 30.0 W 


581 


34.09 


611.9 


30 


10 


11 


133 


29 20.7 N 


132 30.0 W 


2739 


34.62 


665.3 


30 


10 


11 


Evaporimeter sample 




3 r .69 


760.3 


30 


10 


11 


Evaporimeter sample 




33.59 


565.7 


30 


10 


11 


Evaporimeter sample 




37.05 


891.7 


30 


16 


17 


136 


26 12.7 N 


142 02.5 W 





35.36 


734.5 


30 


16 


17 


136 


26 12.7 N 


142 02.5 W 


48 


35.13 


712.4 


30 


16 


17 


136 


26 12.7 N 


142 02.5 W 


95 


34.99 


701.3 


30 


16 


17 


136 


26 12.7 N 


142 02.5 W 


663 


34.15 


618.7 


30 


16 


17 


Evaporimeter sample 




38.22 


994.6 


30 


16 


17 


Evaporimeter sample 




35.25 


722.1 


30 


Oct. 9 


Oct. 10 


143 


34 05.9 N 


157 08.7 W 





34.43 


641.8 


30* 


9 


10 


143 


34 05.9 N 


157 08.7 W 


4 


34.42 


641.5 


30* 


9 


10 


143 


34 05.9 N 


157 08.7 W 


20 


34.44 


644.0 


30* 


9 


10 


143 


34 05.9 N 


157 08.7 W 


• 40 


34.39 


643.2 


30* 


9 


10 


143 


34 05.9 N 


157 08.7 W 


56 


34.19 


619.1 


30* 


9 


10 


143 


34 05.9 N 


157 08.7 W 


163 


34.20 


622.7 


30* 


9 


10 


143 


34.05.9 N 


157 08.7 W 


506 


33.98 


602.3 


30* 


9 


10 


143 


34 05.9 N 


157 08.7 W 


722 


34.09 


609.2 


30* 


9 


10 


143 


34 05.9 N 


157 08.7 W 


1877 


34.59 


657.1 


30* 


15 


16 


146 


31 50.9 N 


140 49.6 W 


22 


34.86 


687.9 


30 


15 


16 


146 


31 50.9 N 


140 49.6 W 


469 


34.01 


603.0 


30 


15 


16 


146 


31 50.9 N 


140 49.6 W 


665 


34.04 


611.2 


30 


15 


16 


146 


31 50.9 N 


140 49.6 W 


764 


34.23 


625.8 


30 


15 


16 


146 


31 50.9 N 


140 49.6 W 


1096 


34.42 


646.0 


30 


15 


16 


146 


31 50.9 N 


140 49.6 W 


1650 


34.53 


656.1 


30 


15 


16 


146 


31 50.9 N 


140 49.6 W 


2173 


34.60 


661,9 


30 


27 


28 


152 


10 04.9 N 


139 43.6 W 





33.67 


568.7 


40 


27 


28 


152 


10 04.9 N 


139 43.6 W 


24 


34.51 


651.3 


40 


27 


28 


152 


10 04.9 N 


139 43.6 W 


188 


34.70 


672.3 


40 


27 


28 


152 


10 04.9 N 


139 43.6 W 
139*13.6 W 


283 


34.68+ 


670.0 


40 


27 


28 


152 


10 04.9 N 


472 


34.61 


661.0 


40 


27 


28 


152 


10 04.9 N 


139 43.6 W 


583 


34.56 


656.4 


40 


27 


28 


152 


10 04.9 N 


139 43.6 W 


870 


34.53 


654.4 


40 


27 


28 


152 


10 04.9 N 


139 43.6 W 


2948 


34.67 


677.5 


40 


27 


28 


152 


10 04.9 N 


139 43.6 W 


3923 


34.68- 


666.3 


40 


Nov. 8 


Nov. 9 


158 


6 33.1 S 


154 58.4 W 





35.57 


752.3 


40 


8 


9 


158 


6 33.1 S 


154 58.4 W 


24 


35.57 


754.0 


40 


8 


9 


158 


6 33.1 S 


154 58.4 W 


73 


35.66- 


760.9 


40 


8 


9 


158 


6 33.1 S 


154 58.4 W 


96 


35.85 


780.5 


40 


8 


9 


158 


6 33.1 S 


154 58.4 W 


193 


35.66- 


762.8 


40 


8 


9 


158 


6 33.1 S 


154 58.4 W 


2260 


34.62 


660.1 


40 


15 


16 


161 


12 03.6 S 


164 57.4 W 





35.52 


746.1 


40 


15 


16 


161 


12 03.6 S 


164 57.4 W 


24 


35.62 


754.5 


40 


15 


16 


161 


12 03.6 S 


• 164 57.4 W 


48 


35.64 


758.1 


40 


15 


16 


161 


12 03.6 S 


164 57.4 W 


72 


35.79 


770.4 


40 


15 


16 


161 


12 03.6 S 


164 57.4 W 


96 


36.04 


791.9 


40 


15 


16 


161 


12 03.6 S 


164 57.4 W 


146 


36.20 


808.9 


40 


15 


16 


161 


12 03.6 S 


164 57.4 W 


191 


35.92 


783.1 


40 


15 


16 


161 


12 03.6 S 


164 57.4 W 


286 


35.14 


709.7 


40 



* Bridge values considered unreliable because of large differences between initial and final standards 



DETERMINATION OF SALINITY 



71 



the date of measurement to determine whether or not 
there had been any change in the bridge calibration 
which might have been caused by differential aging 
among the end coils and slide wire or by corrosion. As 
the differences were not systematic with respect to 
time, no corrections for time were applied. 

These differences were then plotted against their 
respective salinities as given by equation (2). In this 
case systematic differences were found and a smooth 
curve drawn through them. The departures of this curve 
from zero were then tabulated as corrections to be ap- 
plied to the salinities determined from the slide-wire 
readings by means of equation (2). These corrections, 
given in table 2, are largely attributable to irregulari- 
ties in the slide wire. The alternative assumption is 
that these differences arise from variation in composi- 
tion of the salt, and such an assumption would require 
that the composition be an irregular function of the sa- 
linity. Such a relation seems highly improbable. When 
these corrections are applied to the salinities derived 
from equation (2), of the 219 comparisons, 212 differ 
from the titration values by amounts equal to or less 
than 0.04 per mille salinity. This seens to show an even 
greater constancy of salt composition than has been as- 
sumed in the past and leads one to question the accuracy 
of chemical analyses of sea water as published in the 
past. Such published analyses indicate that if solutions 
of each were adjusted to equal concentration, the salin- 
ities as given by titration would differ in some cases in 



Table 2. Corrections to be applied to 

salinities computed from 

second degree equation 



Computed salinity 


Correction 






From 


To 




o/oo 


o/oo 


o/oo 




33.03 


±0.00 


33.04 


33.23 


0.01 


33.24 


33.61 


0.02 


33.62 


33.68 


0.01 


33.69 


33.75 


±0.00 


33.76 


33.83 


-0.01 


33.84 


33.96 


-0.02 


33.97 


34.15 


-0.03 


34.16 


34.44 


-0.02 


34.45 


34.55 


-0.01 


34.56 


34.63 


±0.00 


34.64 


34.71 


-0.01 


34.72 


34.85 


-0.02 


34.86 


34.98 


-0.01 


34.99 


35.15 


±0.00 


35.16 


35.27 


0.01 


35.28 


35.68 


0.02 


35.69 


35.77 


0.03 


35.78 


36.08 


0.04 


36.09 


36.15 


0.03 


36.16 


36.20 


0.02 


36.21 


36.24 


0.01 


36.25 


36.28 


±0.00 


36.29 


36.32 


-0.01 


36.33 


36.57 


-0.02 


36.58 


36.90 


-0.01 


36.91 


37.30 


±0.00 


37.31 


37.69 


0.01 


37.70 


38.10 


0.02 


38.11 




0.03 



the first decimal place of parts per thousand. Obviously 
no such variations were encountered in the cruise of the 
Carnegie . 

As a routine matter the samples of sea water col- 
lected at an oceanographic station in the morning were 
transferred, on arrival at the surface, to glass bottles 
of the citrate-of-magnesia type. These bottles were of 
about 350-cc capacity and were equipped with patent rub- 
ber washer stoppers. The same glass bottles were used 
repeatedly and were used only for sea water. The rub- 
ber washers were replaced as often as their deteriora- 
tion required. To guard further against evaporation, di- 
lution, or contamination of the samples, their salinities 
were measured on the afternoon of the same day they 
were collected. 

The covers were removed from the salinity bridge 
and the stirring motor and thermostatically controlled 
heaters of the water bath were set in operation about an 
hour before measurements were started, in order to 
have equilibrium conditions of temperature established. 
The salinity bridge had three measuring cells, any one 
of which could be switched into the bridge circuit. The 
auxiliary cell had in series with it a small adjustable 
wire-wound resistance which will be called Q for con- 
venience. The first step was to exhaust the measuring 
cells of the water which had been standing in them and 
to fill them with standard water after rinsing them with 
some of the same standard water. The sealed glass tubes 
of Copenhagen standard water were opened only as need- 
ed and their contents transferred to a glass-stoppered 
stock bottle. Any standard water remaining in the stock 
bottle from a previous run was used only for rinsing, 
the cells being filled with water from newly opened tubes. 
The time of filling each cell was then recorded. Fifteen 
minutes after the first cell was filled with standard 
water, the slide wire was set at a reading corresponding 
to the salinity of the standard water and the bridge bal- 
anced by adjusting Q. This adjustment was then tested 
by moving the slide wire and rebalancing the bridge by 
adjusting the slide wire. The setting of Q was correct 
if the slide wire was brought back to its original setting 
to balance the bridge. This reading of Q was then re- 
corded for this particular cell, the standard water was 
removed from the cell which was then rinsed and filled 
with water from one of the samples to be measured. 
Record was made of the time of filling and the identity 
of the sample which took its designation from the num- 
ber on the glass bottle in which it had been stored. Then 
the adjustment of Q was determined for the second cell, 
which in turn was filled with water to be tested. A sim- 
ilar procedure was followed for the third cell. Fifteen 
minutes after the unknown was placed in the first cell, 
Q was set to the reading previously obtained for thr>t 
cell, the cell was switched into the circuit, and the bridge 
balanced by the adjustment of the slide wire. This slide- 
wire reading was recorded and the sample withdrawn 
from the cell, which was then rinsed and filled with water 
from another sample. The time of filling was again re- 
corded and similar operations performed with the other 
cells until all the samples had been measured. As the 
last sample in each cell was removed, it was replaced 
by standard water. This standard water was measured 
exactly as if it were an unknown sample. The difference 
between the slide-wire reading for this final standard 
and its correct value (that for the initial standard) rep- 
resented changes in the cells, changes in the solution in 
the auxiliary cell, or errors in the measurement of 



72 



OBSERVATIONS AND RESULTS IN PHYSICAL OCEANOGRAPHY 



either the initial or final standards. In the absence of 
any evidence to the contrary, it was assumed that this 
difference was the result of a gradual change and the 
difference was therefore proportioned according to the 
number of samples measured in the cell. After this 
shearing correction was applied to the slide-wire read- 
ings, they were converted to salinities by means of the 
previously discussed equation and corrections. The 
final standards were allowed to remain in the measur- 
ing cells until the bridge was used again. A specimen 
set of observations and computations is shown in table 3. 

The design feature of having similar electrolytic 
cells form two adjacent arms of the bridge has, as one 
of its objectives, lessening the importance of accurate 
temperature control. In other words, it was hoped that 
by this device the effective temperature coefficient of 
the instrument would be much less than that of sea water. 
The efficacy of this arrangement was tested on the Car - 
negie as follows: When the regulating temperature of 



the water bath was changed from 30° to 40° C, Copen- 
hagen standard water, which was used as the final stand- 
ard at the end of the last 30° C routine salinity run, was 
left in the cells and was remeasured on the following day 
at 40° C, with the auxiliary resistance Q having the 
same setting as was used at 30° C. The differences in 
slide-wire readings were converted into differences in 
salinity and considered to be the effect produced by a 
10° C change in temperature of a sample. This was done 
on a basis of 1.0 unit on the slide wire corresponding to 
a change of 0.01 per mille in salinity. This procedure 
further was based on the assumptions that during the 
period of about 24 hours the salinity of the solution in 
the auxiliary or Y cell did not change and that the cell 
constants did not change. Such assumptions were justi- 
fiable as only a rough determination was made. The 
slide-wire reading at the balance of the initial standard 
was 698.5 in each case, by definition. Either because of 
changes in cell constants or changes in the auxiliary cell 



Table 3. Specimen set of observations and computations of salinity 



Sam- 
ple 
no. 


Time 


Q 


Ob- 
served 

S. W. 
reading 


Shear- 
ing 
cor- 
rection 


Cor- 
rected 

S. W. 
reading 


Salinity 
from 
equa- 
tion 


Cor- 
rection 


Final 

salinity, 

°/oo 


Depth 

in 
meters 












Cell A 










a 


1:56 


1.124 


698.5 














227 


2:14 


1.124 


645.7 


+ 0.1 


645.8 


34.45 


-0.01 


34.44 


933 


226b 


2:36 


1.125 


628.8 


+ 0.3 


629.1 


34.28 


-0.02 


34.26 


649 


104 


2:55 


1.124 


664.5 


+ 0.4 


664.9 


34.65 


-0.01 


34.64 


3189 


12ic 


3:14 


1.124 


696.3 


+ 0.6 


696.9 


34.97 


-0.01 


34.96 


23 


105 


3:32 


1.124 


697.6 


+ 0.7 


698.3 


34.99 


±0.00 


34.99 


94 


119d 


3:51 


1.124 


654.2 


+ 0.9 


655.1 


34.54 


-0.01 


34.53 


377 


.. a 


4:08 


1.124 


697.5 
698.5 

7| 1.0 

+ 0.1 3/ r 


r 


Cell B 










a 


1:58 


2.016 


698.5 














114 


2:20 


2.016 


660.5 


- 0.1 


660.4 


34.60 


±0.00 


34.60 


1888 


123e 


2:38 


2.016 


658.0 


- 0.2 


657.8 


34.57 


±0.00 


34.57 


1412 


101 


2:59 


2.016 


699.8 


- 0.3 


699.5 


35.00 


±0.00 


35.00 





134 


3:17 


2.016 


698.0 


- 0.4 


697.6 


34.98 


-0.01 


34.97 


46 


111 


3:36 


2.016 


702.7 


- 0.5 


702.2 


35.03 


±0.00 


35.03 


187 


113 


3:54 


2.016 


635.9 


- 0.6 


635.3 


34.34 


-0.02 


34.32 


473 


.... a 


4:14 


2.016 


699.2 
698.5 

7|0.7 

-0.1 


I 


[Telle 










a 


2:04 


2.940 


698.5 














335 


2:26 


2.940 


680.0 


-15.8 


664.2 


34.64 


-0.01 


34.63 


2765 


40lf 


2:41 


2.940 


697.7 


-15.8 


663.9 


34.63 


±0.00 


34.63 


2335 


274 


3:02 


2.940 


711.3 


-15.8 


695.5 


34.96 


-0.01 


34.95 


5 


115 


3:20 


2.940 


718.5 


-15.8 


702.7 


35.03 


±0.00 


35.03 


70 


347g 


3:39 


2.940 


695.5 


-15.8 


679.7 


34.80 


-0.02 


34.78 


281 


110 


3:56 


2.940 


645.4 


-15.8 


629.6 


34.29 


-0.02 


34.27 


666 


.... a 


4:18 


2.940 


714.3 
698. 5 h 

-15.8 


-15.8 













a Copenhagen standard water. b 34.25 per mille by titration by J. H. P., May 28, 1929. c 34.99 
per mille by titration by J. H. P., May 28, 1929. d 34.53 per mille by titration by J. H. P., May 28, 
1929. e 34.55 per mille by titration by J. H. P., May 28, 1929. f 34.64 per mille by titration by 
J. H. P., May 28, 1929. g 34.79 per mille by titration by J. H. P., May 28, 1929. h Initial standard 

discarded as being probably in error. 



DETERMINATION OF SALINITY 



73 



solutions, the slide-wire readings were slightly different 
for the final standard than for the initial standard. If it 
is assumed that these changes were permanent, the 
slide-wire readings for the final standard should be used 
whereas if these changes are assumed to have been tem 
porary and to have disappeared (such as might be the 
case if part of the auxiliary cell solution vaporized dur- 
ing the run and condensed again afterward), then the 
slide-wire readings of the final standard should be used. 
Following the remeasurement of the final standards at 
40°C, they were withdrawn and replaced by other sam- 
ples originally having the same salinity, and another 
series of slide-wire readings taken. Assuming that no 
change in salinity of the final standards had occured, 
the final standard as remeasured should be used. If it 
be assumed that the final standard had changed in salin- 
ity, then the fresh standard should be used. Thus there 
are four combinations per cell which will give a temper- 
ature coefficient of salinity. Their means have been 
taken as shown in table 4. 

These temperature coefficients, even if accurately 
determined, would only apply with the same settings of 
the auxiliary resistance Q. As the settings given above 
approximately represent ohms and as the resistance of 
the cells were about 250 to 300 ohms each, it is seen 
that the uncompensated sea-water resistance was about 
1 per cent of the resistance of the unknown. Taking the 
temperature coefficient of electrical conductivity of sea 
water as 3 per cent per degree centigrade, the tempera- 
ture coefficient of salinity of the bridge would have been 
expected to be of the order of 0.0003 x 35.00 or about 
0.01 per mille per degree centigrade. The general 
agreement between the experimental and calculated val- 
ues indicates that the temperature coefficient of the 
bridge arm containing the Y cell differed from that of 
the arm containing the X cell by not more than 3 parts 
in 10,000. This would not be true generally, but would 
depend on the difference in cell constants of the X and 
Y cells and on the ratio of the resistance of Q to the re- 
sistance of the sea water in the Y cell. It may be noted, 
however, that had a wire resistance been used in place 
of sea water in the Y cell, the temperature coefficient 
would have been in the neighborhood of 0.03 x 35 or about 



1 per mille per degree centigrade. It should be under- 
stood that the wire resistances in the bridge were of 
manganin, having a negligible temperature coefficient, 
and that when measurements were made the X and Y 
cells were accurately at the same temperature. 

Copenhagen standard water was used at every third 
station, substandards being used at the intermediate sta- 
tions. At a station where Copenhagen water was used, 
three large samples were taken, measured, and the sur- 
plus kept until the next station (usually two days later), 
when they were used as standards in the same manner 
as the Copenhagen water was used. At this second sta- 
tion large samples were again measured for use as 
standards at the third station. At the next succeeding 
station, Copenhagen water was again used and the cycle 
repeated. It will be seen then that the possible errors . 
of a single determination of salinity at successive sta- 
tions are 1, 2, and 3 times the error of a single deter- 
mination made at a station where Copenhagen standard 
water was used. The bridge could be balanced to about 
0.002 per mille salinity but the accuracy of the measure- 
ment was not as great as this precision because of the 
uncertainty of the resistance Q, errors in the assump- 
tion that a shearing correction compensated for the dif- 
ference between initial and final standards, and other 
minor factors such as unequal heating caused by the 
test current. Individual measurements were therefore 
accurate to within about 0.02 per mille salinity in terms 
of that of the standard used. Thus, if the salinity of the 
Copenhagen standard water was accurately known, meas- 
urements against such a standard were good to about 
0.02 per mille salinity. Consequently it is possible that 
at stations where a first substandard was used the meas- 
urements might have been in error by 0.04 per mille and 
at stations where a second substandard was used an er- 
ror of 0.06 per mille was possible. This is highly im- 
probable, however, inasmuch as such a situation would 
require all the errors to be made in the same direction 
and, as three different cells were used for the measure- 
ment of samples from each station, such discrepancies 
would probably have been detected in plotting vertical 
distribution curves, unless the standards-ior all three 
cells were in error by similar amounts and in the same 



Table 4. Data for temperature coefficients of salinity for cells A, B, and C 



Cell 



Obser- 


Temper 


vation 


ature 




°C 


I 


30 


II 


30 


III 


40 


IV 


40 


I 


30 


II 


30 


III 


40 


IV 


40 


I 


30 


II 


30 


HI 


40 


IV 


40 



Standard 



Q 



Slide-wire 
reading 



Temperature coefficient 



From 



Value 



Mean for cell A 



B 



Mean for cellB 



Mean for cell C 



Initial 
Final 
Final 
New 



1.913 
1.913 
1.913 
1.913 



d 
698, 
698. 
706 
703 



Initial 


3.048 


698.5 


Final 


3.048 


698.2 


Final 


3.048 


702.6 


New 


3.048 


705.2 


Initial 


3.208 


698.5 


Final 


3.208 


698.7 


Final 


3.208 


712.3 


New 


3.208 


710.1 



I and III 

I and IV 

II and III 
II and IV 


°/oo per °C 
0.0078 
0.0047 
0.0082 
0.0051 

0.0064 


I and III 

I and IV 

II and III 
II and IV 


0.0041 
0.0067 
0.0044 
0.0070 
0.0056 






I and III 

I and IV 

II and III 
II and IV 


0.0138 
0.0116 
0.0136 
0.0114 

0.0126 



74 



OBSERVATIONS AND RESULTS IN PHYSICAL OCEANOGRAPHY 



direction for each station. The best criterion of the 
errors involved jn these measurements is the scatter of 
measured values of salinity of the deep water of the Pa- 
cific. A composite graph showing such salinity values 
from a number of stations when plotted against depth is 
given in figure 2. All measured values from stations 
130 to 149 inclusive and from depths below 1800 meters 
are shown in this figure. The figures opposite the points 
give the number of the oceanographic station at which 
the sample was collected and those which are underlined 
represent stations at which Copenhagen standard water 
was used. It will be noticed that below 2000 meters only 



two points depart from the smooth curve by as much as 
0.04 per mille. This particular group of stations has 
been selected as an illustration because it is one of the 
largest groups in which the deep water has similar char- 
acteristics. Other groups show equally good agreement 
between stations within a group. From these considera- 
tions it is concluded that the salinities determined on the 
Carnegie are reliable to about 0.04 per mille. The re- 
sults of the salinity work are given in the table giving 
the data obtained at the series stations (table 2, I-B), 
and the vertical distribution curves are shown in the 
graphs preceding the tables. 



LITERATURE CITED 



Wenner, F., E. H. Smith, and F. M. Soule. 1930. Appa- 
ratus for the determination aboard ship of the salin- 
ity of sea water by the electrical-conductivity meth- 



od. Dept. Comm. Bur. Stand. Res., vol. 5, pp. 711- 
733. September. Washington. 



- 




1 














' 




— O - 


i 






U. 


- 












5 




9 




5 




> 


- 








3 

3I§ 




£ 


si 


s 


5*5 


5 


i_ 




•r 


5 


?r* 






>» 


=1 




SI §l # s 


i 


s 


flSIS 


T^" 




g 






•Sj 




3 S 




■* 


5IS 




• », 


^***^ \ 






*^ 




s 












■«»■ 


5§i§?3^ 


^ ^' "*■ ^ 






| - 

to ^ 
> 




s 


s -9 




5 










Si" 






3« 


















O ^ <o -j 
























i* > l 

"*J * O Q 

go e » 






5 5 
















v /v/ 


MJdJO 

\ 




^5? 






■<* 


i 




, 7 , 


* 


* 8 


~8313 




to O N , 
m > > > 
■>-■■■■ 


J* 



o 

h- 
< 



i. 



'\ 



\. 



o 

UJ 
Q 



< 



CO 



CO 

u_ 
O 



i i i i i i 



^^_'^ 



75 



ON THE ACCURACY OF THE SALINITY VALUES 



In the preceding chapter Soule has shown that the 
readings of the salinity bridge were converted into terms 
of salinity by means of a calibration curve which was 
obtained by measuring samples in the bridge and titrat- 
ing the same samples by the ordinary silver-nitrate 
method. Owing to this procedure the salinities obtained 
from bridge readings should, on an average, be equal to 
salinities determined by titration, but the accidental er- 
rors of the values would be somewhat greater, amounting 
to +0.04 per mille, mainly since minor deviation from a 
constant temperature exercised a considerable influence 
on the bridge readings. A comparison between the Car - 
negie salinities and those from other expeditions indi- 
cates, however, that the Carnegie salinities are, on an 
average, somewhat too low. This result is arrived at by 
a study of the conditions at great depths where the salin- 
ity is very uniform and where no variations from year to 
year have been detected. 

In his discussion of the deep water of the North At- 
lantic Wiist (1935) writes (in translation): "in our sa- 
linity charts at 1500 to 4500 meters the Carnegie salini- 
ties in the open North Atlantic Ocean appear to be on an 
average 0.03 to 0.04 per mille too low, as also shown 
from a comparison between the TS-curves at the Carne - 
gie stations and neighboring stations from other expedi- 
tions (in single cases the deviations of the Carnegie sa- 
linities vary between -0.10 and 0.02 per mille." 

In the Pacific Ocean the salinity of the deep water 
has been determined on two later expeditions, the Dana 
expedition in 1928 to 1930, and the Bushnell in 1934. 
The Dana observations have not been communicated in 
detail, but some of them have been used in special pub- 
lications. In Schott's (1935) "Geographie des Indischen 
und Stillen Ozeans," salinities and temperatures are 
given at the depth of 3000 meters at a station in latitude 
20° south and longitude 174° east, and at depths of 3000, 
4000, and 5110 meters at a station in latitude 19° south 
and longitude 163° west. These values can be compared 
with Carnegie observations at depths greater than 3000 
meters at stations 87 to 91 which are located between 
latitudes 15° and 18° south and longitudes 145° and 160° 
west. We find: 



Stations 


Lati- 
tude, 

°S 


Longi- 
tude 
°W 


Mean 

depth 

m 


Mean 

temp. 

°C 


Mean 

salinity 

%o 


No. ob- 
serva- 
tions 


Dana 
Carnegie 


19-20 
15-18 


163-186 3775 1.558 34.680 4 
145-160 3357 1.599 34.653 7 



The U.S.S. Bushnell undertook oceanographic work 
in the North Pacific, occupying eighteen stations between 
Adak, Aleutian Islands and Oahu, Hawaiian Islands, to 
depths of 2500 to 3500 meters. The observations! below 
3000 meters can be compared with the Carnegie obser- 
vations below 3000 meters at stations 122, 142, 144, and 



146, of which station 122 is located near the Aleutian Is- 
lands and stations 142, 144, and 146 nearer the Hawaiian 
Islands. We obtain the following table. 



Stations 


Lati- 
tude 
°N 


Longi - 
tude 

°W 


Mean 

depth 

m 


Mean 

temp. 

°C 


Mean 

salinity 

%o 


No. ob- 
serva- 
tions 


Bushnell 50-22 
Carnegie 46-32 


158-170 3396 1.501 34.675 13 
140-174 3637 1.528 34.644 11 



If we consider 34. S7 as the characteristic salinity of 
this region we find that the single Carnegie salinities 
deviate from -0.07 to 0.00 per mille from this value. 
Thus, the range of variation is less than in the North 
Atlantic, indicating that the accuracy of single determi- 
nations was greater during the latter part of the cruise 
than during the first part. 

Compiling these different comparisons we obtain the 
following differences between the salinity of the deep 
water as determined on other expeditions and on the 
cruise of the Carnegie : 



North Atlantic 
0.03 to 0.04 



South Pacific 
0.027 



North Pacific 
0.031 



From the systematic character of these differences 
we must conclude that the Carnegie values of the salini- 
ty of the deep water are about 0.03 per mille too low. 
It follows that all salinity values between 34.6 and 35.0 
per mille are too low by the same amount, but it has not 
been possible to find the cause of this systematic dis- 
crepancy, nor has it been possible to decide whether or 
not a similar discrepancy is present at other values of 
the salinity. 

All tables and graphs had been prepared in final 
form before this systematic discrepancy was discovered, 
for which reason the original Carnegie values have not 
been changed, but in the text attention has been drawn to 
the discrepancy in all cases in which the exact value of 
the salinity of the deep water has been discussed. 

It may be added that the discrepancy will not influ- 
ence the results of the dynamic computations, if it has 
the character of a constant difference, but if the differ- 
ence depends on the absolute value of the salinity, an 
error is introduced in the results of such computations. 
This error will not be serious since it will only influ- 
ence the data from the upper layers and will no doubt be 
smaller than uncertainties arising from lack of knowl- 
edge as to periodic or aperiodic variations in these 
layers. 

* These were kindly placed at the author's disposal 
by the Scripps Institution of Oceanography. 



LITERATURE CITED 



Schott, G 1935. Geographie des Indischen und Stillen 
Ozeans. p. 203. Hamburg. 



Wiist, G. 1935. Wissensch. Ergebn. d. Deut. Atlantischen 
Exped. Meteor 1925-27, vol. 6, no. 1, p. 230, footnote. 



77 



BOTTOM SAMPLES -- COLLECTION AND PRESERVATION 



The bottom samples were collected with samplers 
attached to the end of a hemp lead line which in turn was 
attached to the end of a steel piano wire carried on one 
of the winch drums and led over a meter -wheel at the 
stern of the vessel. The striking of bottom by the sam- 
pler was determined manually by keeping tension in the 
outgoing piano wire with a roller bar. 

Most of the samples were taken with a snapper -type 
sampler- -the sample being caught in a spring-actuated 
clamshell. The snapper -type samplers used varied 
considerably in size, type of trigger, and design of 
weight, but after considerable experimentation, the type 
selected as most suitable to the equipment and condi- 
tions existing on the Carnegie was that shown in figure 
1. Here the pear-shaped lead weight was counterbored 
to fit down over the spring, thus lowering the center of 
gravity. Later the lead weight was so arranged as to be 
left on bottom in order to reduce the strain on the wire 
when hauling in. This was done as follows. The weights 
were cast in halves containing staples in their upper 
ends. When placed on the shank of the snapper they 
were tacked together by. a flat copper staple on each side 
near the bottom of the weight. A wire whose ends were 
made fast to the upper staples passed over the hook of a 
Sigsbee releasing device and held the upper ends of the 
weight together. When the sampler struck bottom, the 
Sigsbee device released the wire, the upper ends of the 



weights fell apart tearing loose the lower staples and 
the two halves fell clear of the snapper and were left on 
the bottom. 

This type of snapper was of sufficient size to y'eld 
about one and one-quarter liters of sample when the bot- 
tom was of ooze, mud, or clay. On striking hard bottom 
it usually collected only a few fragments and the jaws 
were badly dented and had to be repaired. Nodules, cin- 
ders, fragments of obsidian, and similar hard obstruc- 
tions were sometimes caught between the jaws, thus 
permitting the rest of the sample to be washed out on the 
way to the surface. 

A tube sampler intended to give a core sample and 
used on the Meteor was used a few times. It is shown 
in figure 2. This sampler was lined with a removable 
glass tube so that the sample could be inspected and 
stored while still in the lining tube. This type of sam- 
pler was not used more frequently because of its con- 
siderably greater weight and the pull required to with- 
draw it from the bottom put too heavy a strain on the 
piano wire. 

The core samples obtained were stoppered in their 
lining tubes and the samples obtained with snappers 
were transferred to glass bottles and stoppered soon 
after collection. They were then shipped to Washington 
from the next port into which the Carnegie went. 



79 




FIG. I— SNAPPER-TYPE BOTTOM SAMPLER WITH COUNTERBORED LEAD WEIGHT 




FIG.2- METEOR TUBE BOTTOM SAMPLER 
80 



OBSERVATIONS AND RESULTS IN PHYSICAL OCEANOGRAPHY 



II 



RESULTS IN PHYSICAL OCEANOGRAPHY 



CONTENTS 

Page 
Results Within Physical Oceanography H. U. Sverdrup 83 

Figures 1-38 H. U. Sverdrup, J. A. Fleming 115 

Discussion of Carnegie Soundings F. M. Soule 149 

Index 155 



82 



RESULTS WITHIN PHYSICAL OCEANOGRAPHY 



INTRODUCTION 



The present paper was prepared in 1930 to 1931, and 
revised in 1936. In the years 1930 to 1936 a considera- 
ble amount of new data was accumulated from the Pacif- 
ic Ocean. This has not been incorporated in the present 
discussion, since such procedure would have altered the 
entire plan of the publication. The only chapter which 
has been rewritten to some extent is the one dealing with 
the origin of the deep water of the Pacific, because re- 
cent information as to the circulation around the Antarc- 
tic Continent has thrown considerably more light on this 
question and has made more definite conclusions possible. 

The writer takes great pleasure in acknow 1 edging 
the assistance which he has received from members of 
the staff of the Department of Terrestrial Magnetism, 
especially from C. C. Ennis, who undertook a great 
number of the computations, prepared all figures, and 
in the course of this work made a number of valuable 
suggestions. 



It will be readily realized that the careful reduction 
of the extensive observations made during the cruise is 
of paramount importance in any discussion of the re- 
Suits within physical oceanography. The original com- 
putations, compilations, and graphs of this observed 
material were completed under the general direction of 
J. A. Fleming by Martha W. Ennis, C. C. Ennis, W. C. 
Hendrix, and S. L. Seaton, Jr. It will be realized that in 
the course of this work they all made valuable sugges- 
tions which have been incorporated and made use of in 
the present discussion. It will be noted that the general 
results of the discussion are represented in figures 1 
to 38 which follow the text. The graphs of observational 
material above referred to are independently numbered 
as figures 1 to 254 and are reproduced in Oceanography 
I-B. In the text the graphs are referred to as, for ex- 
ample, (fig. 1, I-B). 



THE NORTH ATLANTIC OCEAN 



Temperature, Salinity, and Density 

The physical oceanography of the North Atlantic 
Ocean has been treated by several authors (Jacobsen, 
1929; Helland-Hansen, 1930: Helland-Hansen and Nan- 
sen, 1926; and Wust, 1928) on the basis of modern ob- 
servations. In the following discussion it will be shown 
that the results of the Carnegie observations on the 
whole are in agreement with the previous conceptions as 
to the physical properties of the waters of the North At- 
lantic and as to the character of the circulation. Details 
will be given in only a few cases in which the Carnegie 
observations throw more light on the problems. 

Temperature and Salinity, Stations 1 to 12. - -The 
distances between stations 1 to 12 are so great that the 
results cannot be used for construction of sections; 
therefore, the data from the single stations will be dis- 
cussed separately. Station 1 was in the region of the 
warm water of the Gulf Stream. The vertical distribu- 
tion of salinity and temperature was very much like the 
distribution at station 16, which is located in nearly the 
same latitude but 21° farther east. Even the vertical 
changes of pH and PO4 were similar at the two stations. 

Station 2 reached to 400 meters only, and down to 
this depth there existed a striking similarity to station 
15, which was taken in nearly .the same locality three 
months later. It should be noted that the distance to sta- 
tion 16 from station 15 is not much greater but at this 
station the conditions in the upper 400 meters deviated 
considerably from those at station 2. 

The distances between stations 3, 4, and 5 are small, 
nevertheless the vertical distribution of temperature and 
salinity at these stations differed considerably. Station 
4 reached to 300 meters only, and down to that depth 
showed lower temperatures and lower salinities than the 
two neighboring stations. The difference between sta- 
tions 3 and 5 was especially great at the depths between 



500 and 1500 meters, where the temperature and salinity 
were higher at station 5 than at station 3. The differences 
in the density, at, therefore, had a maximum at about 
700 meters, as shown in table 1. 

Station 6, which is located to the southwest of Ire- 
land, showed still higher temperatures and salinities at 
depths 1000 and 1500 meters. The temperature and sa- 
linity at 1000 meters, 8°50 and 35.52 per mille, respec- 
tively, appear very high, but the Michael Sars, station 
93, (Helland-Hansen, 1930) gave 8.°27 and 35.47 per 
mille on July 25, 1910 in nearly the same locality. 

Stations 7 and 8 are located to the east-southeast of 
Iceland; the former on the Iceland-Faroe Ridge, the lat- 
ter on the shelf surrounding Iceland. At the latter sta- 
tion water of Atlantic character—high temperature and 
high salinity--was found to a depth of more than 700 
meters, whereas at the former the Atlantic water 
reached from the surface down to 200 meters, but the 
characteristic water of the Norwegian Sea was met with 
at the bottom, 454 meters. 



Table 1. Comparison of values of density, at, 
at Carnegie stations 3 and 5, 1S28 



Depth in 


Density, 0" t 


Difference 


meters 


Station 3 Station 5 


(3-5) 






26.69 


26.66 


+ 0.03 


100 


26.96 


26.98 


-0.02 


200 


27.03 


27.04 


-9.01 


300 


27.05 


27.06 


-0.01 


400 


27.11 


27.08 


+ 0.03 


500 


27.20 


27.10 


+ 0.10 


700 


27.41 


27.18 


+ 0.23 


1000 


27.67 


27.58 


+ 0.09 


1500 


27.78 


27.77 


+ 0.01 


2000 


27.81 


27.78 


+ 0.03 



83 



84 



OBSERVATIONS AND RESULTS IN PHYSICAL OCEANOGRAPHY 



At station 9, to the southwest of Iceland, water of a 
relatively high temperature and salinity was still found, 
but at stations 10 and 11 low temperatures were present 
below a depth of 75 or 100 meters, and salinities above 
35 per mille occurred only at some levels above 200 
meters. 

At station 12 the temperature was still lower, name- 
ly 3.°60 at 75 meters, decreasing to 3°30 at 500, 3.°10 at 
1000, and 2.°75 at 2000 meters, whereas the salinity re- 
mained practically constant and equal to 34.87 per mille, 
perhaps increasing slowly with depth below 500 meters. 
The density in situ was almost constant between 75 and 
100 meters, varying between 27.74 and 27.77, but below 
700 meters it increased slowly to 27.86 at 2500 meters. 

The uniform character of the water in the region of 
station 12 has been pointed out by Matthews and consid- 
ered by Jacobsen (1929), who especially discussed the 
opinion of Nansen regarding the origin of the deep water 
of the Western Atlantic Basin. Nansen had indicated that 
the region southeast of Greenland is a place where this 
deep water is formed, because cooling of the surface 
layers in winter may give rise to convective currents, 
which, because of the uniform character of the water, 
may reach to great depths. Jacobsen, however, arrives 
at the result that these processes probably contribute to 
the formation of the uniform water north of the Grand 
Banks of Newfoundland, whereas the true bottom water 
comes from the continental shelf in Denmark Strait. 



Vertical Sections 

The most important results of the work of the Car - 
negie in the Atlantic are represented in the two vertical 
sections I and II. Section I is based on the observations 
at stations 13 to 24 and shows a north and south section 
approximately along the meridian 40° west between lati- 
tudes 46° and 8° north. Section II is from the observa- 
tions at stations 25 to 34 and shows an east and west 
section approximately along the parallel 12° north and 
between longitudes 37° and 79° west. 

Section I . --Section I, comprising stations 13 to 24, 
is taken across the Atlantic Ridge, as is evident from 
the profile of the bottom. Station 13 is situated on the 
Grand Banks of Newfoundland; stations 14, 15, and 16 in 
the Western Atlantic Basin; stations 17 and 18 on the 
ridge; and the rest of the stations, from 19 to 24, are in 
the Eastern Basin. 

The isotherms in Section I (fig. 94; I-B) show the 
well -'mown accumulation of warm water with its center 
at about latitude 30° north. Considering the rapid vari- 
ation in temperature with the distance from the Grand 
Banks, a station on the slope of the Grand Banks would 
have been of value in order to establish the course of 
the isotherms. The double bend of the isotherms south 
of the Grand Banks indicates the existence of a whirl at 
the boundary between the cold water on the southern 
slope of the Grand Banks and the warmer water to the 
south. In this region, but in another location, a similar 
whirl is indicated by the Michael Sars section (Helland- 
Hansen, 1930), which runs a little to the west of the Car - 
negie section. It is probable that changing whirls of dif- 
ferent dimensions are formed at the boundary of the Gulf 
Stream, for which reason the hydrographic conditions in 
a given locality may change rapidly. Our section, there-* 
fore, represents the conditions as observed by the Car - 
negie , but probably not any stationary conditions. 



The isohalines in Section I (fig. 95; I-B) clearly 
show the great accumulation of water of high salinity 
with its center at about latitude 30° north. The isohaline 
35 per mille reaches, at the center, to a depth of more 
than 2000 meters. The whirl to the south of the Grand 
Banks, which was indicated by the temperature distribu- 
tion, is also shown by the course of the isohalines. 

To the south the influence of the intermediate Ant- 
arctic Current is seen in the minimum of salinity at a 
depth between 500 and 1000 meters. The effect of this 
intermediate current reaches, according to the Carnegie. 
at least beyond station 20 or to about latitude 20° north, 
and perhaps can be traced as far as between stations 18 
and 19; or about latitude 26° north. 

At the surface the greatest salinity is found between 
stations 18 and 19, or between latitudes 24° and 30° 
north. From the course of the isohalines, it seems that 
water of very great salinity is spreading to the north 
and to the south at a level of about 100 meters. This 
water represents the type which Jacobsen (1929) has 
called "central water" in his discussion of the results 
of the Dana expedition 1920 to 1922. Jacobsen shows, in 
agreement with the Carnegie results, that at a level of 
about 100 meters this water is flowing away from the 
region in which it is being formed, the Sargasso Sea re- 
gion. 

The deep water appears to have a salinity slightly 
below 34.90 per mille in both the Western and Eastern 
basins, but the Carnegie values are probably 0.03 to 
0.04 per mille too low. 

The density curves in Section I (fig. 96; I-B) show 
especially that the difference in density between stations 
15 and 16 reaches a maximum somewhere below the 
surface. When discussing the conditions at stations 3 
and 5 (p. 30 and table 1), it was pointed out that the 
greatest difference in density was found at a depth of 
about 700 meters. Table 2 is the result of an examina- 
tion of stations 15 and 16. Here we find a considerable 
difference in the upper layers, reversal of sign, and a 
new maximum at about 500 and 700 meters. 

Table 2. Comparison of values of density, cr^, 
at Carnegie stations 15 and 16, 1928 



Depth in 
meters 



Density, at 



Station 15 



Station 16 



Difference 
(15-16) 






24.47 


23.95 


+ 0.52 


100 


26.28 


25.94 


+ 0.32 


200 


26.41 


26.41 





300 


26.42 


26.61 


-0.19 


400 


26.44 


26.80 


-0.36 


500 


26.49 


26.93 


-0.44 


700 


26.77 


27.25 


-0.48 


1000 


27.30 


27.58 


-0.28 


1500 


27.73 


27.77 


-0.04 


2000 


27.79 


27.80 


- 0.01 


Section II. 


--Section II, 


stations 25 to 34, 


runs ap- 



proximately east and west, following the parallel of 
about 12° north from 37° to 79° west longitude. It be- 
gins in the Eastern Basin of the Atlantic in which sta- 
tions 25 and 26 are located, and continues across the 
ridge (with station 27 on the ridge), into the Western 
Basin in which stations 28, 29, and 30 are situated. It 
then crosses the threshold of the Caribbenn Sea, in 
which the last four stations--31, 32, 33, and 34--are lo- 
cated. 



THE NORTH ATLANTIC OCEAN 



85 



At the surface the temperature (fig. 210; I-B) is uni- 
form and high—between 25° and 30° C. In the Caribbean 
Sea we find in the upper layers a greater accumulation 
of warm water than in the Atlantic, the isotherms of 10° 
and 15° being found at greater depths in the Caribbean. 
The observations below a depth of 1000 meters in the 
Caribbean Sea indicate that below this depth the temper- 
ature remains almost constant. At all stations it de- 
creases slightly with increasing depth, but the decrease 
is so slow that the deepest observation gives a tempera- 
ture of 4.°07 at a depth of 2287 meters, against 3.°20 at 
the same depth outside the Caribbean Sea (station 30). 
The observations of the Dana in the Caribbean Sea 
(Jacobsen, 1929) give, on an average, a similar result, 
as is evident from table 3. 

Table 3. Temperature below 1000 meters in the 
Caribbean Sea according to the Dana and the Carnegie 





Depth in meters 


Source 


1000 1500 2000 


Dana (8 stations) 
Carnegie (4 stations) 


o o o 

4.98 4.22 4.09 
4.91 4.15 4.08 



The observations at great depths by the Dana indi- 
cate a rise of the temperature from a level of 2000 or 
2500 meters toward the bottom, corresponding approxi- 
mately to adiabatic equilibrium. 

In the Atlantic part of Section II the temperature de- 
creases regularly toward the bottom, the lowest value 
observed being 2.° 17 at a depth of 4703 meters at station 
30. 

The salinity curves in Section II (fig. 101; I-B) show 
a maximum below the surface at a depth of about 100 
meters. This maximum, as already pointed out by Jacob- 
sen, is probably related to the existence of currents 
which carry salt water from the central part of the .At- 
lantic Ocean to the south. 

The salinity minimum at a level of about 700 meters, 
indicating the intermediate Antarctic Current, is clearly 
seen. It also is evident that this intermediate water pen- 
etrates the Caribbean Sea, but here it probably becomes 
mixed with the overlying and underlying water since the 
salinity of the intermediate water increases somewhat 
when proceeding to the west. These features have been 
treated thoroughly by Jacobsen, who especially has ex- 
amined the mixing of the water masses of different ori- 
gin. 

The Carnegie observations indicate a decrease in 
the salinity of the water of the Caribbean Sea below a 
depth of 1000 meters, but this decrease is probably not 
a real feature in spite of the fact that it is shown by the 
observations at two stations, 33 and 34. At the former 
a salinity of 34.76 per mille was observed at a depth of 
2075 meters, and at the latter a salinity of 34.74 per 
mille at 2287 meters. The observations of the Dana be- 
low a level of 1200 meters, however, show a uniform 
salinity varying between 34.95 per mille and 34.98 per 
mille. The observed values at the greatest depths of 
stations 33 and 34 therefore have been rejected and, in- 
stead, it was assumed that the salinity at a level of 2000 
meters was 34.96 per mille at both stations. When car- 
rying out the dynamic calculation this value was used. 



The Deep Water of the Atlantic 

Temperature. --Helland-Hansen (1930) has shown 
that the Challenger observations indicate that the bottom 
temperatures decrease with increasing depth in the 
Western Atlantic Deep, but increase in the Eastern At- 
lantic Deep. Introducing the potential temperature, 6, 
defined as the temperature which a water particle attains 
when it is raised adiabatically to the surface of the sea, 
he found that the potential temperature decreases with 
increasing depth in the Western Deep but remains con- 
stant in the Eastern Deep. The ai)solutf values are low- 
er in the Western Deep and this result is confirmed by 
the observations of the Dana. 

We have table 4 as a result of an examination of the 
potential temperature of the water below a depth of 4000 
meters according to the Carnegi e observations. The 
data are too few to permit any conclusions as to the av- 
erage conditions in the two basins, except that the poten- 
tial temperature is lower in the Western Deep than in the 
the Eastern. It may be added that all values in the East- 
ern Deep are lower than the average value, 2.°15, found 
by Helland-Hansen from the Challenger observations. 

Salinity . --Table 5 is the result of the observations 
of salinity below a level of 4000 meters. The salinity 
appears to be slightly lower in the Eastern Deep, but the 
values are too few and show too much scattering to per- 
mit any definite conclusions. The absolute values are, 
as stated on page 72, probably 0.03 to 0.04 per mille too 
low. 

Table 4. Values of potential temperature, Atlantic 
deep water, Carnegie, 1928 



Western deep 



Station Depth 8 



Eastern deep 



Station Depth 



15 



m 
4061 


1.86 


19 


m 
4091 
4616 
5148 


2.10 
2.03 
1.96 


4319 
4841 


2.01 
1.90 


21 


4126 


2.07 






23 


4076 


2.06 



30 4703 1.73 




Mean 4481 1.88 4411 2.04 


Table 5. Values of salinity, Atlantic deep water, 
Carnegie, 1928 


Western deep 


Eastern deep 


Station Depth | S, 


Station Depth | S, 



14 



15 



m 


%o 




m 


°/oo 


4061 


34.89 


19 


4091 
4616 
5148 


34.87 
34.80 
34.83 


4319 


34.89 








4841 


34.85 












21 


4126 


34.87 






23 


4076 


34.81 



Mean 



4407 



34.88 



4411 



34.84 



86 



OBSERVATIONS AND RESULTS IN PHYSICAL OCEANOGRAPHY 



For comparison we add table 6 which shows the 
mean potential temperature and the salinity at an ap- 
proximate depth of 4500 meters according to the obser- 
vations of Challenger, Dana , and Carnegi e. 

Table 6. Mean potential temperature and salinity, 
Atlantic deep water, Carnegie, 1928 



Source 



Western deep 



Eastern deep 



Challenger 

Dana 

Carnegie 



%>o 

2.00 

1.91 (16) 34.89 (17) 

1.88 (4) 34.88 (3) 



%o 
2.15 

2.08 (9) 34.90 (9) 
2.04 (5) 34.84 (5) 



The number of observations are shown in parenthesis 

The temperatures of the Challenger appear to be 
about 0.°1 too high. The Dana and Carnegie tempera- 
tures agree well; but the Dana salinities are 0.035 per 
mille higher on an average. 



Temperature-Salinity Relation 

The temperature-salinity (tS) diagrams, which were 
introduced by Helland-Hansen (1918), have proved very 
helpful in the discussion of the origin and the mixing of 
the different types of water in the oceans. The tS dia- 
grams therefore have been plotted for each station. 

Jacobsen (1929) has discussed the character of the 
waters of the North Atlantic by means of the tS dia- 
grams from the Dana expeditions. A comparison shows 
that the data from the Carnegie are, on the whole, in 
good agreement with the data which Jacobsen discusses. 
A similar discussion therefore would not lead to any new 
conclusions. We have seen (pp.30, 31)that we found rather 
different conditions at the neighboring st-tions 3, 5, 15, 
and 16, and it is of interest to examine the extent to 
which water of a similar character is met with at these 
stations. 

In figure 1 the tS curves for these four stations 
have been plotted. It is seen that they all agree quite 
well and that no considerable deviation's from an average 
normal tS relation occur. Below a depth of 700 meters, 
however, where the discrepancies between the stations 
are found, we find agreement between the conditions at 
stations 3 and 16, and from 1000 and 1500 meters we 
find agreement at stations 5 and 15. Therefore, it can 
hardly be doubted that the water of high salinity and high 
temperature which is found between 700 and 1500 meters 
at station 5 comes from the west. On the other hand, it 
is not very probable that we can trace a continuous flow 
of this water from the region of station 15 to the region 
of station 5, because station 3 falls between the two lo- 
calities. It is more probable that in both localities we 
deal with whirls which develop at the boundary of the 
strong Atlantic Current. 

For comparison the tS diagram for station 6 has 
been shown in the same figure. This curve has a widely 
different course and at the depth of 1000 meters the de- 
viation from the normal tS relation is very great. Ac- 
cording to Helland-Hansen and Nansen this deviation in 
the region of station 6 must be ascribed to the influence 
of the Mediterranean water. When discussing the data 



from this station, it was pointed out that the high tem- 
peratures and salinities are, as a rule, found between 
700 and 1500 meters in the region where the station was 
occupied. 

We shall not enter any more into detail as to the tS 
relations, but shall draw attention to some major fea- 
tures. When discussing the vertical sections we saw 
that a marked difference exists between the Carnegie 
stations north and south of latitude 20° north. To the 
south of this latitude the characteristic salinity minimum 
of the intermediate Antarctic Current is found at all sta- 
tions, but to the north of this latitude the salinity de- 
creases toward the bottom without any intermediate 
minimum. The tS relation therefore is quite different 
at the stations north and south of latitude 20° north. In 
figure 2 the data for observations at stations north of 
20° north and below a level of 100 meters have been 
plotted, using different designations for observations in 
the depth intervals 100 to 500, 500 to 1500, and below 
1500 meters. It is seen that all values fall nearly on a 
mean curve. This agrees well with the corresponding 
curves which Helland-Hansen has derived from the ob- 
servations on board the Michael Sars and the Armauer 
Hansen which are also shown in the diagram. A few 
values fall above the lines, and these originate from re- 
gions where the Mediterranean water is found. 

Another feature of considerable interest is that in 
the northern Atlantic the occurrence of water of a cer- 
tain tS relation is not restricted to certain intervals of 
depth. Water of high temperature and high salinity is 
found in the upper layers only, but in other localities in 
the upper layers one finds water which has the proper- 
ties of the water between 500 and 1500 meters at other 
stations, or even the properties of the deep water. This 
feature indicates that a considerable vertical circulation 
exists within the area of the North Atlantic where the 
observations have been made and that the deep water 
may be mixed with water which has been at the surface. 

To the south of latitude 20° the salinity minimum 
is plainly seen in the tS diagram in figure 3, which 
shows a much more pronounced stratification of the 
water. Water of a temperature above 12° is never found 
below 500 meters, of a temperature below 7° never 
above 500 meters, and of a temperature below 4° never 
above 1500 meters. Therefore, a direct transport of 
surface water down to the greatest depth does not take 
place in the region from which these observations orig- 
inate. This result is self-evident because all the obser- 
vations were taken in the tropics, but the stratification 
has been pointed out here because it will be shown that 
the corresponding stratification is more pronounced in 
the Pacific. Figure 4 shows the tS relation on a more 
open scale for depths below 1400 meters. Short vertical 
lines on the various curves designate the approximate 
limiting depths within which the respective temperature 
and salinity values were obtained. Such designation was 
not made in figure 3 on the curve for the North Atlantic 
(stations 1 to 19) because of the varying characteristics 
of the water and the relative meagerness of data for 
depths below 1000 meters. 

The temperature -salinity diagrams for each station 
are shown in figures 201 to 209, I-B. Because of insuf- 
ficient data, no further detailed discussion of the char- 
acteristic properties of the water at different levels and 
in different regions of the North Atlantic will be at- 
tempted. 



THE NORTH ATLANTIC OCEAN 



87 



Results of Dynamic Calculations 

Helland-Hansen and Nansen (1926) have published 
maps of the eastern North Atlantic showing the topogra- 
phy of a number of isobaric surfaces relative to the to- 
pography of the 2000-decibar surface, and Jacobsen 
(1929) has published corresponding maps of the greater 
part of the North Atlantic using the 1000-decibar sur- 
face as a basis. Most of the Carnegie stations reach to 
greater depths than 2000 meters and the results, there- 
fore, can be used for amplifying the maps by Helland- 
Hansen and Nansen. 

Figure 5 shows the topography of the 100-decibar 
surface relative to the topography of the 2000-decibar 
surface, based on the anomalies in dynamic meters of 
the distances between the surfaces. The lines repre- 
senting the relative topography of the 100-decibar sur- 
face are drawn for intervals of 10 dynamic centimeters. 
The relative flow of the water at a pressure of 100 deci- 
bars is parallel to the lines and in the direction which is 
indicated by the arrows. The flow of the water at a 
pressure of 2000 decibars is undoubtedly very slow and 
the lines, therefore, represent very nearly the direction 
of the absolute currents at the depth where the pressure 
is 100 decibars, or at a depth of about 100 meters below 
the surface. 

The continuous lines in the figure have been copied, 
with afew simplifications, from Helland-Hansen and Nan- 
sen's map. These lines are based on numerous obser- 
vations over a period of many years and must, there- 
fore, be expected to represent nearly a true picture of 
the average topography of the 100-decibar surface in the 
stated units. The corresponding values at the Carnegie 
stations are entered in the same units. Some of the 
Carnegie stations fall within the area which has been 
examined by Helland-Hansen and Nansen, and the values 
at these stations are in excellent agreement with their 
map, except the value 1.30 to the northwest of the Azores. 
It is very probable, however, that this station is situated 
in a region where minor whirls occur, such as those 
which are indicated at other localities in Helland-Hansen 
and Nansen's map. The broken lines in the figure rep- 
resent the relative topography of the 100-decibar sur- 
face according to the Carnegie data outside the region 
which previously had been studied. It is seen that these 
lines can be readily united with Helland-Hansen and 
Nansen's lines. As we proceed from north to south, 
along the route of the Carnegie, we recognize the Lab- 
rador Current, the Atlantic Drift, the anticyclonic cir- 
culation around the Sargasso Sea, and the north equato- 
rial trade-wind drift, which partly continues into the 
Caribbean Sea. 

Figure 6 shows the profile of the isobaric surfaces 
0, 100, 200, 300, 400, 500, 700, 1000, and 1500 decibars 
along Section I, referred to the 2000-decibar surface. It 
is evident that the currents are strongest in the upper 
layers because the slopes decrease with increasing 
depth. It especially should be noted that the 1500-deci- 
bar surface is almost level when referred to the 2000- 
decibar surface, meaning that the currents at 1500 me- 
ters vary but little from the currents at 2000 meters. 



There are strong reasons for assuming the currents to 
be very weak at a depth of 2000 meters and we can, 
therefore, regard the relative slopes in the figure as 
representing very nearly the actual slopes of the sur- 
faces. The section runs approximately north and south, 
and a slope to the north represents a current to the east, 
and vice versa. 

To the right in the figure the steep slope between 
stations 15 and 16 indicates the Gulf Stream. The maxi- 
mum velocity of this current is reached, according to 
the slope of the isobaric surfaces, at a level of about 200 
meters. Examining the difference between the elevations 
of the isobaric surface above the 2000-decibar surface, 
we find: 



Isobaric 
surface 



Decibars 
100 200 300 400 500 700 1000 1500 
Dynamic meters 



Difference in 
elevation 
(15-16) .32 .41 .44 .41 .38 .34 .25 .12 .03 

The slope of the 200-decibar surface is thus the 
greatest and remains considerable down to a depth of 
more than 1000 meters. 

Aside from the maximum elevation of the isobaric 
surfaces at station 15 which must be associated with 
the presence of whirl, we find the maximum elevation of 
the 0-decibar surface at station 20, or i,n latitude about 
20°, but the maximum shifts toward the north with in- 
creasing depth and at the 200-decibar surface is found at 
station 18, or latitude 30°-. Between stations 18 and 20 
we find, thus, a current which is directed toward the 
east at the surface but toward the west at a depth of 200 
meters; below 500 meters it is again directed toward 
the east. 

Disregarding what are probably local conditions be- 
tween stations 15 and 16, the strongest westerly current 
is found between stations 20 and 21. This westerly cur- 
rent, in contrast with the Gulf Stream, has the greatest 
velocity at the surface, but it decreases so rapidly with 
depth that the current is weak below 500 meters. Exam- 
ining the differences between the elevations of the iso- 
baric surfaces we find: 



Isobaric 
surface 



Decibars 
100 200 300 400 500 700 1000 1500 
Dynamic meters 



Difference in 
elevation 
(20-21) .24 .23 .17 .13 .10 .08 .07 .05 



.03 



South of station 20, that is, south of latitude 20°, the 
current is, on the whole, directed toward the west, but 
irregularities appear to be present. 

A corresponding examination of the profiles of the 
isobaric surface along the parallel of 12° north, Section 
II, does not produce definite results, which indicates that 
in this region the east and west currents are much 
stronger than the north and south currents. 



THE PACIFIC OCEAN 



General 

Prior to the last cruise of the Carnegie the knowledge 
of the physical oceanography of the Pacific Ocean was 
based on results of expeditions which had been under- 
taken before 1910, the major part of these expeditions 
having been in the last decades of the nineteenth century. 
Only the expeditions in the early part of the twentieth 
century were equipped with accurate thermometers and 
carried out determinations of the salinity with the pre- 
cision which now is regarded as necessary. None of 
the expeditions which have obtained reliable information, 
however, have operated at great distances from land or 
in the central part of the ocean. Our knowledge of the 
conditions of the open ocean is, therefore, primarily 
based on measurements which do not meet the present 
requirements as to accuracy. This applies especially to 
the observed salinities but the temperatures are also 
inaccurate, as will be shown later when discussing the 
Carnegie data in detail. 

The older observations from the Pacific, however, 
have given a general view of the thermal and haline 
characteristics of the waters in the different regions and 
especially have thrown light over the major features of 
the stratification of the waters. It has been possible to 
draw conclusions as to the circulation of the upper strata 
of the ocean but it has not been possible to disclose the 
character of the deep-water circulation. 

The woeful lack of knowledge concerning the temper- 
ature and salinity of tne deep water of the Pacific prior 
to the Carnegie observations is illustrated in figure 7 
which shows the location of stations at which observations 
of temperature and salinity for depths greater than 3000 
meters had been made by earlier expeditions (according 
to Wust), as compared with those of the Carnegie . 

Schott and Schu (1910) have discussed the tempera- 
ture of the Pacific waters on the basis of the entire mat- 
erial which was available at that time. The isothermal 
maps which these authors have drawn for the different 
levels give a good general view of the distribution of 
temperature, and the major features in their maps are 
undoubtedly correct. 

Conclusions as to the circulation can hardly be drawn 
on the basis of temperature maps only. Wust (1929) made 
use of the observations of density and salinity which had 
been made on earlier expeditions for the construction of 
two salinity sections, one representing the salinities in 
the western part of the Pacific and the other the salini- 
ties in the central part. He also constructed temperature 
sections. The sections through the western Pacific are 
based, to a considerable extent, on the later observations 
of the Planet expedition and therefore are more trust- 
worthy than the sections from the central Pacific which 
are based only on the Challenger's observations, except 
for the most northern and southern regions. It will be 
shown later that the temperatures of the Challenger can- 
not be regarded as having the accuracy which Wust as- 
sumed, and that the salinities which were used for con- 
structing the sections are inaccurate in spite of the great 
improvements which Wust introduced by his methods. 
But, notwithstanding the deficiencies in material, the 
sections give a correct representation of the more con- 
spicuous features of the stratification of the waters. We 
shall, therefore, briefly discuss these sections in order 
to obtain a general view of the conditions in the region 



which later will be treated more in detail by means of 
the Carnegie observations. Since it is possible to con- 
struct a new section from the Carnegie data, however, 
we shall use this as representative of the central Pacif- 
ic and use the section by Wust for the western Pacific. 
The Carnegie section for the central Pacific deviates in 
important details from the corresponding section by 
Wust, but the major features in which we now are inter- 
ested are the same. The four sections with which we 
are dealing are represented in figures 8 to 11. 

The temperature distribution (figures 8 and 10) in 
the Pacific Ocean is almost symmetrical as to the equa- 
tor in contrast with the temperature distribution in the 
Atlantic. In the Pacific we find accumulations of warm 
water both in the Northern and Southern hemispheres. 
In the central Pacific the warm water reaches almost to 
the same latitude in both hemispheres, but in the west- 
ern Pacific the extension toward the south is greater 
than the extension toward the north. In both sections the 
warm water reaches deeper in the Southern Hemisphere 
and here we have, therefore, the greater accumulation 
of warm water. In both sections, at about latitude 10° 
north we find only a very thin layer of warm water, but 
the highest temperatures for 1000-meter depths are 
found in this latitude. In both sections the temperature 
decreases rapidly down to a depth of a few hundred me- 
ters. From this depth the decrease continues slowly and 
regularly to the bottom. The isotherms in the western 
section show several bends but in the central section 
they have a smooth course. There we find none of the 
temperature inversions so characteristic of the corre- 
sponding sections from the Atlantic and Indian oceans. 

The salinity distribution (figures 9 and 11) does not 
show such a pronounced symmetry as the temperature 
distribution. The accumulation of water of high salinity 
is more conspicuous in the Southern Hemisphere where 
the vertical extension is greater and where it reaches a 
greater distance from the equator. This accumulation is 
more developed in the western than in the central section. 
The accumulation in each hemisphere is separated from 
the other by a belt of water of low salinity which follows 
approximately the parallel of 10", the same latitude in 
which the isotherm of 20° approaches the surface. 

Below the accumulations of water of high salinity in 
both hemispheres we find water of very low salinity 
which appears to penetrate toward the equator from the 
subarctic and subantarctic regions, representing the in- 
termediate subpolar currents. In the Atlantic this inter- 
mediate current is developed only in the Southern Hem- 
isphere but reaches across the equator up to about lati- 
tude 20°. In the Pacific the intermediate current appears 
to be developed almost to the same extent in both hemi- 
spheres. In the Northern Hemisphere it penetrates to 
almost 15° in both the central and western sections; in 
the Southern Hemisphere it penetrates to almost 20° in 
the central section and to 30° in the western section. In 
these sections, however, the salinity curve 34.4 per 
mille has been used as representing the last traces of 
the intermediate water, but if 34.5 per mille had been 
used, we would have found that the intermediate water 
penetrates to between latitudes 15° and 10° in the North- 
ern Hemisphere and to between latitudes 0° and 10° in 
the Southern Hemisphere. 

Between the last traces of the intermediate water, 
in the equatorial part of both sections, we find water of 



88 



THE PACIFIC OCEAN 



89 



a salinity which is lower than the salinity of both- the 
surface and the deep water. 

The deep water which fills the Pacific Basin below 
a depth of 2000 meters, is, according to these sections, 
of a very uniform character, with a temperature slightly 
below 2° and a salinity somewhat above 34.6 per mille. 

Defant (1928) has pointed out the adyantage of dis- 
tinguishing between two different horizontal strata in the 
sea, namely: an upper stratum, the troposphere, within 
which great variations of temperature and salinity in 
horizontal and vertical directions are found, and to which 
the most important currents are confined; and a deeper 
stratum, the stratosphere, which is characterized by 
small variations in temperature and salinity both in hor- 
izontal and vertical directions, and consequently, by 
very slow currents. In the Pacific, in accordance with 
Wiist, we may regard the isothermal surface of 10° as 
separating the troposphere from the stratosphere. We 
find then that the troposphere has a maximum vertical 
extension of about 650 meters in the western Pacific and 
of less than 500 meters in the central Pacific, and that 
the stratosphere reaches to the curface of the sea north 
and south of latitudes about 50° north and south, respec- 
tively. The circulation within the troposphere, also in 
accordance with Wiist, will be called the warm-water 
circulation, and the circulation within the stratosphere 
will be called the cold-water circulation. 



The Available Data 

The observations of the Carnegie are not so numer- 
ous that by means of these we can undertake a complete 
discussion of the physical oceanography of the Pacific. 
Most of the observations were made north of latitude 20° 
south. Observations south of this latitude are available 
only from the South American coast to longitude 120° 
west. Thus no stations were occupied in the greater 
part of the South Pacific south of latitude 20° south, and 
in the North Pacific great regions have not been visited. 
Considering these wide gaps, it might appear desirable 
to amplify the data of the Carnegie by means of data 
from earlier expeditions, in order to make the best pos- 
sible use of the existing material in the following dis- 
cussion. None of the earlier observations from the Pa- 
cific, however, are of the same quality as to accuracy 
as the Carnegie data except later observations which 
have been taken off the coast of California, in the Gulf of 
Alaska, in the Japanese waters, and the observations of 
the Planet between New Guinea and Japan. Most of these 
observations do not reach to as great depths as those at 
the Carnegie stations. They are well suited for the study 
of details in the different regions but they contribute lit- 
tle to the knowledge of the major features which enter in 
the foreground when dealing with the work of the Carne - 
gie . We shall, therefore, make use only of some stations 
in the Gulf of Alaska which directly form a supplement to 
the Carnegie stations in this region. 

As to the older observations, it has already been 
emphasized that these are less accurate than the later 
ones. In order to illustrate this the vertical tempera- 
ture distribution at three Challenger stations and three 
Carnegie stations (which were taken in approximately 
the same localties) is represented in figure 12. It is 
seen that the general features of the temperature dis- 
tribution agree well, but the results differ considerably 
in details. Comparing the stations Challenger 254 and 



Carnegie 143 we find that the Carnegie observations 
show a decrease of the temperature at all levels, where- 
as the Challenger observations show three inversions. 
The two lower inversions, however, fall between levels 
at which the Carnegie observed, and at the latter levels 
agreement exists between the Challenger and Carnegie 
temperatures. It is possible, therefore, that the inver- 
sions existed when the Carnegie station was occupied 
but escaped detection because the observations were 
made at too great intervals. A comparison between sta- 
tions Challenger 262 and Carnegie 139 shows that this 
conception can hardly be upheld. The Carnegie station 
again shows a decrease of temperature at all levels, 
whereas the Challenger station indicates a succession of 
intervals with small decrease or inversions. At this 
station the intervals of the Carnegie observations are 
again much greater than the intervals of the Challenger 
observations, but a Carnegie observation was made at 
the level at which a Challenger observation indicates an 
intermediate minimum of l.°56. The Carnegie observa- 
tion shows no such minimum but the value lies practi- 
cally on the straight line joining the two adjacent obser- 
vations. The irregularities of the Challenger values 
which occur above a level of 500 meters are actually of 
the same order of magnitude as the irregularities at a 
greater depth but they are less conspicuous because of 
the rapid change of temperature with depth. The obser- 
vations at the two stations Challenger 280 and Carnegie 
87 agree, on the whole, very well but below a level of 
800 meters the Challenger temperatures appear to be as 
much as 0°3 too high. 

These three examples show that the reality of the 
small inversions which were observed at great depths on 
the Challenger must be doubted and the same also ap- 
plies to the intervals with small temperature gradients 
in the upper layers. Such irregularities are never found 
at the Carnegie stations, as is evident from the temper - 
ture curves of the following figures reproduced in I-B: 
94, 100, 106, 112, 118, 127, 133, 142, 148, 154, 160, 166, 
172, 178, 187, and 196. 

It is true, as already mentioned, that the Carnegie 
observations have been made at greater intervals than 
the Challenger observations, but if inversions at great 
depths were as frequent as indicated by the Challenger 
data, they would undoubtedly have been observed at 
some stations and have changed the smooth course of the 
curve. Considering this circumstance we cannot agree 
with Wiist in accepting the small inversions as repre- 
senting actual conditions. The Carnegie observations 
strongly indicate that, although the Challenger data give 
a true representation of the major features of the tem- 
perature distribution, the details cannot be relied on. 
This result is in agreement with the conception of the 
officers of the Challenger because, in the report on the 
deep-sea temperature observations, smooth curves have 
been drawn by means of the observed data and the values 
scaled from curves have been given beside the observed 
values. The smooth curves agree, on the whole, with 
the Carnegie curves, and the results from the upper lay- 
ers could be used for amplification of the Carnegie data, 
but the deep-sea temperatures from the two expeditions 
are not comparable. 

With the exception of the later expeditions referred 
to previously, the observations of temperature by the 
other expeditions which have cruised in the Pacific have 
not been made by means of more superior methods. It 
is not advisable, therefore, to combine the results of 



90 



OBSERVATIONS AND RESULTS IN PHYSICAL OCEANOGRAPHY 



these earlier expeditions with the Carnegie results. The 
same applies, to a still greater extent, to the salinities. 
Numerous observations of the salinity have been made 
by the Challenger but, as stated before, these have not 
the accuracy which permits combination with modern 
data. The following discussion of the physical oceanog- 
raphy of the Pacific will be based, therefore, principally 
on the Carnegie data alone. 



Temperature and Salinity 
Horizontal Distribution 

The values of temperature and salinity, scaled from 
graphs for each station, have been entered in figures 
210-233; I-B, and isotherms and isohalines have been 
drawn in order to bring out the characteristic features. 
It must be emphasized, however, that at the higher levels 
these lines have no well-defined physical significance. 
They do not represent the values at a given moment nor 
the mean annual values because the observations have 
been made in different seasons in the different regions. 

In the upper layers great deviations from the aver- 
age annual conditions must be expected because of sea- 
sonal variations in heating and cooling. In the courses 
of the currents and because of irregular changes, but at 
greater depths, such variations are probably small and 
here the lines can be expected to represent the average 
conditions, although they are based on a small number of 
observations. 

By means of earlier observations, Schott and Schu 
(1910) have prepared charts showing the horizontal dis- 
tribution of temperature at different levels down to a 
depth of 4000 meters, and Schott (1928) has published a 
chart showing the distribution of the salinity at the sur- 
face. In the following we shall undertake some compari- 
sons between these charts and those derived from the 
Carnegie data. 

Surface . --At the surface (figure 210; I-B) the tem- 
perature in the Northern Hemisphere decreases regular- 
ly from the equator toward the north in the western part 
of the Pacific. In the eastern part of both hemispheres 
the isotherms are bent toward the equator but more so 
in the Southern Hemisphere, where a region of low tem- 
perature can be followed along the equator from the Pe- 
ruvian coast toward longitude 150° west. In the western 
part of the ocean a corresponding bend of the isotherms 
toward the equator is found to the northeast of Japan, 
going from Bering Sea down to latitude 40° north. 

The chart by Schott and Schu shows the mean annual 
isotherms and, therefore, it cannot be expected that the 
Carnegie data will agree with the chart values because 
of the annual variation of the surface temperature. The 
Carnegie observations were made in summer in both 
hemispheres, for which reason they must be higher as a 
rule than the means for the year. Comparing the Car - 
negie data with the corresponding values which can be 
read off the Schott-Schu chart, we find that the Carnegie 
temperatures generally are higher. The most striking 
exception is in the vicinity of the Galapagos Islands, 
where, at stations 41, 42, 43, 44, and 45, the average de- 
viation from the chart values is -2?2. 

It is not possible to reduce the Carnegie observa- 
tions to the mean of the year because sufficient data as 
to the annual variation are lacking. The Marine Impe- 
rial Institute at Kobe, Japan has published mean monthly 



isotherms for the greater part of the North Pacific, but 
the charts do not cover the entire area in question. For 
the equatorial regions Puis (1895) has published monthly 
isotherms, but these do not quite agree with the above- 
mentioned in the areas where the two representations 
overlap. In order to eliminate the effect of changes in 
the currents on the temperature distribution (Helland- 
Hansen, 1930) it would be necessary, furthermore, to 
take the salinity variations into account, but isohalines 
for each month are not available. The foundation for a 
reduction of the observed temperatures to the mean of 
the year is, thus, insufficient, but we can draw attention 
to the character of the differences between the Carnegie 
values (C) and the mean annual temperatures as repre- 
sented by Schott and Schu (SS) and by Japanese charts 
(Tap) . We also shall examine the differences between the 
Carnegie data and the corresponding mean monthly val- 
ues as shown in Japanese charts and in those by Puis. 

Forming mean values we find for the North Pacific, 
from stations 98 to 140: C-SS = +1.°9, 

C - Jap. (year) = +2.°0, 

C - Tap (month) = +0.°7; 
for the equatorial regions, from stations 35 to 47: 

C - SS = -lfl. 

C - Puis = -0.°1; 
from stations 70 to 74, 93 to 109, 138, 139, and 149 to 
162: C-SS = +1?5, 

C - Puis = +0.°5. 
The differences between the Carnegie observations 
and the values from the Schott-Schu chart are shown in 
table 7, where they have been arranged in groups accord- 
ing to the latitude, and where the months in which the 
observations were taken, are shown. The table also con- 
tains the differences in salinity according to the Carnegie 
observations and Schott's chart to which we shall return 
presently. In this place it will be pointed out that the 
Carnegie observations give the relatively highest tem- 
peratures in the middle part of the North Pacific in the 
months of September and October and the relatively low- 
est values, aside from the conditions in and near the 
Gulf of Panama, in the equatorial region in April and 
May. 

Table 7. Differences in temperature and salinity 

between the Carnegie observations (CJ and the values 

from charts by Schott and Schu (SS) and Schott (S) 



Stations 



Latitudes 



Months 
1928-1929 



Tem- 
per- 
ature 
C-SS 



Salin- 
ity 
C-S 





o o 








°C 


°/oo 


35- 48 


7N-20S 


Oct., 


Nov. 




-1.0 


-0.06 


49- 68 


20 S 


Nov. 


, Dec. 


, Jan. 


+ 1.5 


-0.34 


69- 93 


10 S-20S 


Jan., 


Feb., 


Mar. 


+ 2.1 


-0.18 


94-108 


20 S-20N 


Apr. 


, May 




+ 0.3 


-0.23 


109-129 


20 N 


May, 


June, 


July 


+ 2.0 


-0.20 


130-149 


20N 


Sep., 


Oct. 




+ 3.6 


+ 0.01 


150-162 


20N-20 S 


Oct., 


Nov. 




+ 1.5 


-0.19 



These features, and the fact that the differences are 
reduced when comparing with monthly charts, indicate 
that the discrepancies between the Carnegie observations 
and the annual values according to Schott and Schu prin- 
cipally are because of the annual variation of the surface 
temperature, but part of the variation is probably con- 
nected with accidental changes in the currents. 



THE PACIFIC OCEAN 



91 



The surface salinity (fig. 222; I-B) shows a less 
symmetrical distribution than the temperature. Two 
maxima of salinity are found, one in the Southern, and 
one in the Northern Hemisphere. The former has its 
center in the eastern part of the ocean in approximately 
latitude 20° south and longitude 120° west, whereas the 
latter has its center in the western part of the ocean in 
approximately latitude 25° north and longitude 175° east. 
These two areas of high salinity are separated by a 
narrow belt of low salinity in about latitude 10° north, 
the lowest salinities occurring in the eastern part of the 
ocean. Near Central America the salinities are very 
low, probably because of local conditions. To the north 
and the south of the areas of high salinity, the surface 
salinity decreases toward the poles. This decrease ap- 
pears to be greater in the Northern Hemisphere, where 
salinities approaching 32.5 per mille are found in the 
inner part of the Gulf of Alaska and to the northeast of 
Japan. 

The chart of the surface salinity by Schott repre- 
sents approximately mean annual isohalines, but in sev- 
eral regions the observations on which the mean annual 
values are based, are distributed unevenly over the year 
and the actual annual values may, therefore, deviate 
somewhat from the values of the chart. 

The Carnegie data are smaller than the values by 
Schott on the whole. Negative differences are found in 
eighty-seven of one hundred and twenty-eight cases and 
positive differences in nineteen cases only. As a rule, 
the differences are small and equal to or smaller than 
0.3 per mille in ninety-one instances. The mean of all 
is -0.17 per mille. 

Within the equatorial region no relation exists be- 
tween the simultaneous deviation from the mean values 
of temperature and salinity. This becomes evident when 
plotting the corresponding values in a temperature- 
salinity diagram, and is also evident from table 7, which 
contains the corresponding average values for certain 
regions. Outside the equatorial regions, on the other 
hand, we find a distinct relation between the correspond- 
ing deviations: on the average a high temperature cor- 
responds to a high salinity, and vice versa. This is seen 
when plotting the corresponding deviations and is also 
evident from table 7 where, within the three areas out- 
side the equatorial regions, we find for values of t, l.°5, 
2.°0, and 3.°6 and the values of S are -0.34, -0.20, and 
+ 0.01 per mille, respectively. 

An increase of 1° in the temperature deviation thus 
appears to correspond to an increase of 0.15 per mille 
in the salinity deviation. This increase corresponds to 
the normal temperature-salinity relation which is found 
in the Pacific. The relation found between the deviations 
from the chart values, thus can be interpreted to indi- 
cate either that the annual variations in temperature and 
salinity are parallel to one another, or that part of the 
temperature deviations have nothing to do with the an- 
nual variation of temperature but are caused by changes 
in the currents and, therefore, are accompanied by par- 
allel variations in salinity. At present it is impossible 
to decide which of these factors is of the greater impor- 
tance. 

One hundred-meter level . --At this level the temper- 
ature distribution (fig. 211; I-B) is already materially 
changed and the difference between the conditions in the 
eastern and western parts of the ocean is much more 
pronounced. Here we find a temperature of 12° off Cal- 
lao, which increases as one proceeds toward the west, 



reaching 20° at the meridian of 100° west, whereas at 
the surface the corresponding temperatures are 18° and 
23°. Off San Francisco we find a temperature of 9° in- 
creasing to 14° at the meridian of 140° west, whereas 
the corresponding surface values are 13° and 16°. The 
most conspicuous feature, however, is that north of the 
equator in about latitude 10° north and longitude 140° 
west a temperature of 11° is found where the surface 
value is about 24°. 

Comparingthe Carnegie observations at 100 meters 
with the values by Schott and Schu, we find deviations 
of a less systematic character than at the surface. 
Within wide areas the deviations are small and of chang- 
ing sign, the mean of all being 0.°37. Deviations greater 
than 5° are found off Japan, to the south of Bering Sea, 
and to the north of the equator between the parallels of 
5° and 15° north, in the region of the Equatorial Counter - 
current. 

The Schott-Schu chart shows a belt of tempera- 
tures below 20° stretching across the ocean in about 
latitude 10° north and separating the warm water mass- 
es of the two hemispheres. In the figure this belt of low 
temperatures is shown in the eastern part of the ocean 
only, but it must be admitted that in the western part the 
distances between the stations are so great that the fea- 
ture may have escaped observation. 

The seasonal variation of temperature due to the 
influence of heating and cooling is probably very small 
at the 100-meter level (Helland-Hansen, 1930). The dif- 
ference, therefore, cannot be ascribed to such seasonal 
variations, but must be related to changes in the currents. 
These changes may be of an accidental or periodic 
character and influence both temperature and salinity 
distribution. We have no means of examining corre- 
sponding temperature and salinity deviation, but the 
fact that the greatest differences in temperature occur 
in regions where strong and varying currents prevail, 
indicates that the discrepancies are owing to displace- 
ment of these currents. 

The distribution of the salinity at the 100-meter 
level (fig. 223; I-B) shows the same features as at the 
surface, but the difference between the western and 
eastern part of the ocean is more pronounced. Very low 
salinities are found off the Peruvian and Californian 
coasts. The minimum north of the equator is less pro- 
nounced. 

Two hundred-meter level . --The temperature dis- 
tribution (fig. 212; I-B) shows a new and interesting fea- 
ture. At this level the belt of low temperatures to the 
north of the equator can be followed across the ocean as 
far as the observ?tions are extended, and a similar belt 
appears to be present directly to the south of the equa- 
tor, whereas higher temperatures prevail at the equator. 

The typical region of low temperature, which at 
higher levels could be followed from the coast of Peru 
toward the west along the equator, has now moved to the 
south and is found entirely in the Southern Hemisphere. 

In the Schott-Schu chart only one belt of low tem- 
peratures to the north of the equator is seen, -the second 
belt to the south of the equator is not present. It is pos- 
sible that the existence of the two belts is connected 
with the special development of the currents at the time 
when the Carnegie observations were made, but even if 
this is the case, the feature is characteristic of the con- 
ditions in the central Pacific. 

The average discrepancy between the Carnegie ob- 
servations and the corresponding values according to 



92 



OBSERVATIONS AND RESULTS IN PHYSICAL OCEANOGRAPHY 



Schott and Schu is of the same order as at the 100-meter 
level and the greatest deviations are found, as previous- 
ly, where strong currents prevail. 

The character of the salinity distribution (fig. 224; 
I-B) is not much changed except that the difference be- 
tween the conditions in the northern and southern parts 
of the ocean is more prominent. In the Northern Hemi- 
sphere salinities above 35 per mille occur only within a 
narrow strip where the temperature exceeds 20°, 
whereas in the Southern Hemisphere salinities above 35 
per mille are found over a wide area stretching toward 
the east into regions where the temperature is consider- 
ably lower than 20°. Here isolated areas with a salinity 
above 36 per mille are present. Off the coast of Chile 
we find a tongue of low salinity in the region where a 
corresponding tongue of low temperature is present. 

Three hundred-meter level. --At this level we find, 
principally, the same distribution of temperature (fig. 
213; I-B) as at 200 meters. The two belts of low tem- 
peratures on both sides of the equator and the high tem- 
peratures between them appear more clearly, and the 
tongue of low temperatures off the Peruvian coast has 
moved somewhat farther south. The warm-water accu- 
mulations in both hemispheres are more clearly sepa- 
rated. 

The distribution of salinity (fig. 225; I-B) is more 
uniform than at higher levels. In the Northern Hemi- 
sphere the accumulation of water of high salinity is seen 
in the eastern part only, but the values do not exceed 
34.7 per mille. In the Southern Hemisphere the accumu- 
lation of very salty water is still fairly well developed 
with values above 35 per mille in a wide region. 

In both hemispheres tongues of low salinity pene- 
trate toward the equator in the western part of the ocean. 
In the Northern Hemisphere the tongue nearly coincides 
with a corresponding tongue of low temperatures, but in 
the Southern, the low salinities are found considerably 
more to the south than the low temperatures. 

Four hundred-meter level. --The temperature dis- 
tribution (fig. 214; I-B) is principally the same as at 300 
meters, but the differences between the values in differ- 
ent parts of the ocean are smaller. At this level a con- 
nection is clearly seen between the two equatorial belts 
of low temperature and the tongue of low temperature in 
the western part of the ocean. The discrepancies be- 
tween the Carnegie data and the Schott-Schu chart are of 
the same character as previously. 

The salinity distribution (fig. 226; I-B) also shows 
the same features as at 300 meters, but now only traces 
of the accumulation of water of high salinity are present, 
and the tongues of water of low salinity on the western 
side of the ocean are still more pronounced. 

Five hundred-meter level. --Here we find again a 
similar distribution of temperature (fig. 215; I-B), but 
the high temperatures at the equator appear more clear- 
ly and to the north of the equator we find alternating high 
and low temperatures where, at higher levels, there was 
a belt of low temperatures only. The highest tempera- 
tures are found in the Northern Hemisphere where there 
are values above 10° in the eastern part of the ocean. 

The distribution of salinity (fig. 227; I-B), on the 
other hand, is much changed as compared with the dis- 
tribution at higher levels. At 500 meters we find no 
trace of accumulations of water of high salinity in ei- 
ther hemisphere, but the maximum values are found 
along the equator where, however, they remain lower 
than 34.65 per mille. The tongues of low salinity on the 



western side of the ocean are still present, and in the 
Northern Hemisphere salinities lower than 34.1 per 
mille appear to be characteristic of the entire central 
part of the North Pacific. 

Seven hundred-meter level. --Here the temperature 
contrasts (fig. 216; I-B) are still smaller, but the char- 
acter of distribution is not much changed. Traces of 
the warm-water accumulations are still seen in both 
hemispheres, and the characteristic tongues of low tem- 
peratures at the western side of the ocean can be fol- 
lowed. 

At this level the highest salinities (fig. 228; I-B) are 
also found at the equator, but the values nowhere exceed 
34.60 per mille. In the Southern Hemisphere a tongue of 
low salinity is still present at the western side of the 
ocean, but in the Northern Hemisphere the correspond- 
ing tongue has disappeared and the lowest values are 
found in the central part of the North Pacific. 

One thousand- meter level. --At this level a consid- 
erable change in the character of the temperature dis- 
tribution (fig. 217; I-B) has taken place. In the equato- 
rial region we find alternating strips of low and high 
temperatures. In the Northern Hemisphere the temper- 
ature decreases fairly regularly toward the north, but 
now there are high temperatures off the coast of Cali- 
fornia, where at higher levels low temperatures prevail. 
In the Southern Hemisphere the tongue of low tempera- 
ture in the western part of the ocean is still present, but 
it has been displaced somewhat to the south. 

At this and lower levels the charts by Schott and 
Schu show higher temperatures, on the whole, than do 
the Carnegie observations. Detailed comparison is of 
minor interest because the data on which the charts are 
based are less accurate than the Carnegie observations. 
The distribution of the salinity (fig. 229; I-B) is very 
similar to the distribution at 700 meters, but the con- 
trasts are smaller and the maximum values in the vi- 
cinity of the equator are also smaller. 

Fifteen hundred-meter level. --Here the tempera- 
ture distribution (fig. 218; I-B) in the Northern Hemi- 
sphere has the same character as at 1000 meters, but 
in the Southern Hemisphere the characteristic tongue of 
low temperatures has disappeared, and instead, a tongue 
of high temperature stretches toward the south in longi- 
tude 95° west. As to the distribution of the salinity (fig. 
230; I-B), the maximum values are still found in the 
equatorial region and are now slightly above 34.6 per 
mille and the low values in the central part of the North 
Pacific have almost disappeared. 

Two thousand- meter level. --The temperature dis- 
tribution here (fig. 219; I-B) is similar to the distribu- 
tion at 1500 meters, but the contrasts are smaller. The 
highest temperatures, above 2.°3, are found near the 
equator, whereas the lowest values, l.°8, are directly to 
the south of Bering Sea. The salinity (fig. 231; I-B) is 
higher than at 1500 meters. Values below 34.6 per 
mille are found off the coast of Chile, in a limited area 
near the Samoan Islands, and in the greater part of the 
North Pacific. 

Twenty-five hundred-meter level. --At this level the 
temperature distribution (fig. 220; I-B) shows new and 
interesting features. Temperatures above l.°9 are found 
in the vicinity of the equator and in the southern part of 
the South Pacific, whereas in the northern part of the 
South Pacific temperatures slightly below l.°9 appear to 
prevail. In the North Pacific an area with temperatures 
below l.°7 covers the northern part, but in the Gulf of 



THE PACIFIC OCEAN 



93 



Alaska, to the south of Bering Sea, and off the coast of 
Japan, slightly higher temperatures are present. The 
distribution of the salinity (fig. 232; I-B) at this level is 
so uniform that no isohalines can be drawn, but a gener- 
al decrease of the salinity from south to north appears 
to be characteristic at this level. Values approaching or 
slightly surpassing 34.7 per mille are found at the most 
southern stations, whereas in the North Pacific the sa- 
linity is only slightly above 34.6 per mille. 

Three-thousand-meter level. --The temperature dis- 
tribution (fig. 221; I-B) here is very uniform. Near Cen- 
tral America values above 2.°0 are observed, but else- 
where the temperature varies between l.°85 in the basin 
off the Peruvian coast to l.°55 in the central part of the 
North Pacific. The lowest values again appear to be 
present in the northern part of the North Pacific, where- 
as high values prevail in the equatorial region. The 
material is very scanty, but the variations are suffi- 
ciently systematic to give significance to the isotherms 
which have been drawn. At this level the salinity (fig. 
233; I-B) appears to decrease from south to north, vary- 
ing from 34.68 per. mille in latitude 40° south to 34.63 
per mille in latitude 40° north. In the southern part the 
values are approximately the same as at 2500 meters, 
but in the northern part they are slightly higher. 

Concerning the salinities it must be added that these, 
according to the discussion given on page 72, appear 
to be about 0.03 per mille too low. This systematic er- 
ror is of no importance in the upper levels but at great 
depth it exerts an influence on the course of the isoha- 
lines. 

The warm water of the Pacific. --We have seen that 
at the 700-meter level the distribution of both tempera- 
ture and salinity is quite different from the distribution 
at higher levels. Therefore, we conclude that the warm - 
water circulation in no locality reaches as far down as 
the 700-meter level. At the 500-meter level traces of 
this circulation were seen in the temperature distribu- 
tion only, and considering that the temperature at 500 
meters is lower than 10° and that we have previously 
regarded the isothermal surface of 10° as representing 
the lower boundary of the troposphere, we conclude that 
the warm-water circulation practically has disappeared 
below the 500-meter level. 

Intermediate water of the Pacific. --The intermedi- 
ate water of low salinity is first clearly seen at the 400- 
meter level in the eastern part of the North Pacific 
where the low salinities off the Gulf of Alaska continue 
toward latitude 25° and bend toward the west somewhat 
to the north of this latitude. The isotherms show a 
corresponding but less pronounced bend toward the west. 
In the Southern Hemisphere the corresponding interme- 
diate current appears to be present in the region to the 
west of South America. At the 500-meter level the in- 
termediate current evidently reaches farther west in the 
Northern Hemisphere as indicated by the course of the 
isohalines and also by the characteristic bend of the iso- 
therms. At the 700-meter level the intermediate cur- 
rent is less strongly developed in the eastern part of the 
North Pacific where the salinities now are higher than 
at the 500-meter level. The lowest salinities are now 
found farther west. In the Southern Hemisphere the 
intermediate current can be traced up to about 15°. At 
the 1000-meter level we are evidently below the inter- 
mediate current because the salinities are higher here 
than at 700 meters both north of latitude 20° north and 



south of latitude 20° south. The intermediate current 
thus appears to be most strongly developed between 
depths of 400 and 700 meters in the Northern Hemi- 
sphere, and to lie at a higher level in the eastern part of 
the ocean. In the Southern Hemisphere it appears from 
the horizontal charts to be most prominent at a level of 
700 meters. The last traces of the intermediate cur- 
rents do not reach to lower latitudes than about 15° and 
10°. Between these latitudes we find water of a uniform 
salinity which is higher than the salinity of the interme- 
diate currents but lower than the salinity of the deep 
water. 

Deep water of the Pacific. --The deep water of the 
Pacific is very uniform; the temperature decreases 
slowly with increasing depth and the salinity increases 
slowly. In a horizontal direction we find a decrease of 
salinity from south to north and maximum temperatures 
at the equator, but the total range of temperature is less 
than 0°2, except the local conditions near Central Amer- 
ica. The uniform character ofthe deep water is illus- 
trated by the following table, which shows average values 
of temperature and salinity at the depths 2000, 2500, and 
3000 meters within stated intervals of latitude. It is seen 
seen that the range of the average temperatures de- 
creases slowly with depth whereas the range of the aver- 
age salinities remains equal to 0.04 per mille, and the 
absolute values decrease from south to north at each 
level. But as a result from a general discussion of the 
salinity values, it seems probable that salinities as tab- 
ulated and graphed should be increased by 0.03 per 
mille. The discussion on which this conclusion is based 
is presented in Physical Oceanography I-B of the "Sci- 
entific results of cruise VII of the Carnegie ." 

Vertical Distribution 

When discussing the horizontal distribution of tem- 
perature and salinity we considered the most prominent 
features of the vertical distribution and especially em- 
phasized that the waters of the Pacific show a typical 
stratification both as to temperature and salinity. Turn- 
ing to a more detailed discussion of the vertical distri- 
bution, we shall base this on the representations in the 
vertical sections and shall also make use of the curves 
which show the observed data at each station. As to the 
construction of the sections we refer to the explanation 
of the graphs. 

Section HI. --Section III embraces stations 37 to 40 
and 60 to 72, begins near the Gulf of Panama, follows the 
coast of South America down to latitude 17° south, and 
continues south- southwest to latitude 40° south. Two 
stations in the Gulf of Panama, stations 35 and 36, were 
not included when constructing the section. 

The topmost layer of the troposphere has been called 
by Defant the zone of agitation (St^rungszone), repre- 
senting the layer within which convection currents can 
mix the water thoroughly. It is perhaps better to use the 
term convection layer because this term better express- 
es the character of this uppermost stratum. 

Off Central America the convection layer is very 
thin. At station 35 it does not reach to 27 meters and 
has a salinity of 29.8 per mille and a temperature of 
about 27.°5. At stations 36, 37, 38, and 39 the thickness 
of the layer is between 20 and 30 meters. The salinity 
increases up to 33 per mille at station 39. The temper- 
ature is about 27° at the previous three stations and 



94 



OBSERVATIONS AND RESULTS IN PHYSICAL OCEANOGRAPHY 



about 25° at station 39. At station 40 the convection 
layer has a thickness of less than 23 meters, the salin- 
ity is slightly above 34 per mille but the temperature is 
only 20. c 4. At the next stations, 69 to 72, we also find a 
very thick convection layer which never reaches to a 
depth of 40 meters. The surface salinity is higher here, 
being above 35 per mille, but the temperature is low 
especially at station 71 which has been taken at a short 
distance from the coast. Proceeding toward the south 
along the section we find that the convection layer re- 
mains thin at all stations, but the transition from the 
convection layer to the deeper layers becomes more and 
more gradual. This is especially evident when we take 
the density into account. At station 71 we have, for in- 
stance, an increase in o^ from 24.05 at 19 meters to 
25.36 at 40 meters, whereas at station 60, CTj. increases 
only from 25.32 to 25.51 between 24 and 47 meters. 

The heating by radiation and contact with the atmos- 
phere and the influence of evaporation and precipitation 
are primarily responsible for the temperature and the 
salinity of the convection layer, but transport of water 
from deeper layers may also be of importance. In this 
place we shall especially emphasize that the low salinity 
in the region of Central America must be ascribed to 
the influence of precipitation because we have no inflow 
of water of low salinity to this region, and because no 
large rivers carry considerable quantities of freshwater 
into the sea. The high salinities off the Peruvian coast, 
on the other hand, must be attributed to the effect of 
evaporation because this water is transported toward the 
coast from the south where the salinity is lower, or to 
the effect of "upwelling" which brings water of higher 
salinity to the surface. 

Below the convection layer we find a more or less 
rapid decrease of the temperature with increase with 
depth. The decrease is especially very rapid at the 
stations which have been taken at a short distance from 
the coast of Peru, but is more gradual at the southern 
stations. The isotherm of 15° sinks from stations 60 to 
67 and rises between stations 67 and 70. The isotherm 
of 10° also sinks between stations 60 and 67 but up to 
station 71 this isotherm continues sinking and runs hori- 
zontally north of this station. The isotherm of 5°, on the 



other hand, runs almost horizontally up to station 67 and 
sinks from this station as it proceeds to the north. The 
rise of the isotherm of 15° between stations 67 and 70 
indicates an accumulation of cold water in the upper 
layer; but this accumulation does not reach below the 
level of the 10° isotherm and is thus a phenomenon of the 
troposphere. 

The distribution of the salinity is much more com- 
plicated except in the northern part of the section where 
the salinity decreases regularly down to a depth of 1000 
meters. South of station 72 we find many irregularities 
in the vertical variation of the salinity at the different 
stations, but in the section two major features are seen. 
The salinity of the water above a depth of about 200 me- 
ters increases, on the whole, from south to north. As 
already mentioned, this increase must be attributed to 
the influence of evaporation because it is more rapid at 
the surface. The tongue of low salinity, which extends 
from station 68 to station 70 at a depth of 150 to 200 me- 
ters, is probably associated with an upwelling movement 
in the upper layers. Below a level of 400 meters we find 
a layer of minimum salinity representing the intermedi- 
ate antarctic current. The axis of the lowest values 
sinks from a little less than 500 meters at station 60 to 
about 700 meters at station 69, and in the same distance 
the salinity increases from 34.2 to 34.5 per mille. The 
axis practically follows the isotherm of 6°. To the north 
of station 69 water of salinity between 34.5 and 34.6 per 
mille is found between depths of about 500 and 1500 me- 
ters. 

The deep water below a level of 2000 meters has a 
very uniform character. The salinity increases slightly 
toward the bottom. „ 

In the Peruvian Basin the temperature appears to 
have a constant value of l. c 83 below a level of 2700 me- 
ters, but at the southern stations, 60 to 66, the tempera- 
ture decreases with increasing depth. The lowest tem- 
perature was found at station 60 where l.°23 was observed 
at a depth of 3617 meters, 400 meters above the bottom. 

Section IV. --Section IV, comprising stations 45 to 51, 
also represents a section approximately north and south 
in the same general region but at a greater distance from 
the coast. Here the convection layer has a considerably 



Table 8. Deep-sea temperatures (t) and salinities (S) in the Pacific arranged according to latitude 



Area 


Number 

of 
Stations 


Depth in meters 


Lati- 


Longi- 
tude 


2000 


2500 


3000 


tude 


t, °C i S, %o 


t, °C ; S,°/oo 


t, °C ; S, o/oo 



40 N 120 W 12 1-91(12) 34.58(12) 

40 N 140 V 

20 N 120 W 29 2 - 04 ( 29 ) 34 - 59 ( 2 9) 



20 N 140 E 
130 W 




20 S 



180 
70 W 



18 2.19 (16) 34.62 (16) 
44 2.20 (42) 34.62 (42) 



20 S 120 W 

41 S 70 W 20 2.17(19) 34.62(19) 



Maximum - minimum 



0.29 



0.04 



1.71 (11) 34.61 (11) 

1.74 (27) 34.62 (27) 

1.84 (15) 34.63 (15) 

1.89 (41) 34.64 (41) 

1.90 (18) 34.65 (18) 
0.19 0.04 



1.62 (7) 34.63 (7) 

1.60 (19) 34.63 (19) 

1.69 (12) 34.64 (12) 

1.77 (24) 34.66 (24) 

1.76 (12) 34.67 (12) 

0.17 0.04 



Numbers in parentheses indicate number of stations included. Salinities probably 0.03 o/oo too low. 



THE PACIFIC OCEAN 



95 



greater thickness, especially in the central part of the 
section, where at station 48 it reaches to almost 80 me- 
ters, and at station 45 it exceeds 60 meters, but at sta- 
tion 51 it reaches to less than 25 meters. The zone of 
rapid transition sinks as one proceeds to the south along 
the section. The distribution of temperature does not 
show any other conspicuous features. 

The salinity has high values at the surface, surpass- 
ing 36.00 per mille between stations 47 and 50. A tongue 
of salinity'above 36.00 per mille stretches past station 
47 to the north, which indicates a transport of water of 
high salinity at a depth of about 100 meters. In the south- 
ern part of the section the intermediate antarctic cur- 
rent is recognized by the tongue of low salinity at a level 
of about 700 meters. The axis of the lowest values ap- 
parently rises as it proceeds toward the north and 
reaches a level of about 600 meters to the north of sta- 
tion 48. The axis again nearly coincides with the iso- 
therm of 6° and this isotherm shows a corresponding 
but smaller rise. The deep water has the same uniform 
character as in the preceding section. 

Section X. --Section X (stations 51, 52, and 55 to 60) 
runs from southeast to northwest from station 51 to 60. 
The convection layer is thin at all stations, and exceeds 
30 meters only at stations 55, 56, and 57. The isotherms 
sink toward the northwest in the upper layers, which in- 
dicates that we approach the warm-water accumulation. 
Below 800 meters they run horizontally. 

The salinities are also highest to the northwest, 
where values above 35.5 per mille are found, and where 
the course of the isohalines indicates that water of high 
salinity is spreading toward the southeast. In the most 
southeastern part of the section we find very low surface 
salinities, probably characteristic of the easterly cur- 
rent in this region. The decrease of the surface salinity 
in a horizontal direction is especially rapid in the region 
of station 57, and here the northern limit of the easterly 
current may be sought. The belt of salinity below 34.4 
per mille at a depth of 600 to 800 meters represents the 
intermediate antarctic current. The axis of the lowest 
values is found at approximately 800 meters at station 
51 and rises to about 650 meters at station 60. At sta- 
tions 51 to 57 the axis follows the isotherm of 5° but at 
stations 58 to 60 it follows the isotherm of 5.°5. The 
isotherms in these 'ayers, however, also show a rise 
toward the southeast which corresponds to the rise of 
the axis. The deep water has a temperature which de- 
creases regularly with increasing depth, but the salinity 
of the deep water shows a more irregular distribution. 
At stations 58 to 60 salinities above 34.7 per mille have 
been observed, being the highest values which were found 
below the 2000-meter level. 

Section XI . --This section (stations 71 to 93) runs 
practically east and west, and follows approximately the 
parallel of 18° from the Peruvian coast to the Samoan 
Islands. 

In the eastern part of the section, off the South 
American coast, the convection layer is very thin, only 
about 20 meters as a rule, but the thickness increases 
toward the west and exceeds 50 meters at several sta- 
tions. 

In the western part of the section, which is taken in 
the central region of the South Pacific Ocean, we find an 
accumulation of warm water which reaches to a depth of 
more than 400 meters, if we regard the isotherm of 10° 
as representing the lower limit of the warm water. High 
temperatures, above 25°, are found to thewest of station 



78 only, and the isotherms of 20° and 15°, which are 
found at a considerable depth in the central part of the 
ocean, rise almost to the surface as they approach the 
coast. The rise of these isotherms indicates an accu- 
mulation of cold water at the coast, but this accumula- 
tion is characteristic of the upper layers only because 
the isotherms below 300 meters are horizontal or sink- 
ing as they near the coast. Thus all isotherms below the 
isotherm of 7° are found at a lower level off the Peruvi- 
an coast than in mid-ocean. 

The salinity distribution in the troposphere is char- 
acterized by high values to the west of station 77. At 
most stations a salinity maximum is found at a short 
distance below the surface and this must be attributed 
either to the influence of seasonal variations or to the 
existence of subsurface currents which transport water 
of high salinities from regions south of the section. The 
isohalines rise as they approach the South American 
coast, which shows that the cold water at the coast has a 
low salinity. The salinity decreases very rapidly with 
increasing depth between 200 and 300 meters, and at a 
depth of 600 or 700 meters we find in the whole section 
low salinities representing the northern part of the in- 
termediate antarctic current. The axis of the layer of 
low salinity sinks slightly toward the coast and runs on 
an average, at a level of about 650 meters in the eastern 
part. The temperature along the axis is nearly 5.°5 over 
the whole distance, and the sinking of the axis nearly 
corresponds to the sinking of the isotherms. The bot- 
tom water is very uniform, the isotherms running near- 
ly horizontally, but the salinity appears to be higher at 
the same level near the South American coast than in 
mid-ocean. 

Section XII. --Section XII (stations 40 to 45) also 
runs approximately east and west and follows nearly the 
parallel of 2° from the South American coast to longi- 
tude 105°. The section thus represents conditions in the 
eastern part of the Pacific very near the equator. 

The convection layer is very thin at the coast but 
increases systematically toward the west, and has a 
thickness of nearly 60 meters at station 45. The tem- 
perature in the upper layer is very low, remaining be- 
low 23° at all stations and being lower than 20° at sta- 
tions 42 and 43. These stations were within the area of 
low temperature which, according to the chart showing 
the temperature distribution at the surface, stretches 
toward the west from the South American coast. The 
temperature decreases rapidly directly below the con- 
vection layer, but this rapid decrease takes place in a 
short distance only. 

The salinities on the whole are low, especially at a 
short distance from the coast, and show a maximum at a 
level of approximately 100 meters, perhaps representing 
a transport of water from the southwest at this level. A 
layer of low salinity is also found in this section, and it 
lies deeper than in the previously discussed sections. 
The minimum is not very pronounced, the lowest values 
being higher than 34.5 per mille. The axis of the lowest 
values is found at approximately 900 meters where the 
temperature is about 5°. The isotherm of 5° sinks 
slightly toward the coast but the salinity minimum is not 
so well defined that the axis of this minimum can be 
traced with any certainty, for which reason it cannot be 
seen whether or not this axis deviates from the horizon- 
tal direction. The deep water is again very uniform with 
a temperature which decreases slowly with increasing 
depth and a salinity which increases slowly. 



96 



OBSERVATIONS AND RESULTS IN PHYSICAL OCEANOGRAPHY 



Section V. - -Section V, comprising stations 130 to 
134 and 148 to 162, runs from San Francisco toward the 
southwest to Samoa. It passes through regions of dif- 
ferent character and we shall, therefore, first discuss 
the part of the section which lies between latitudes 20° 
north and 20° south, namely, stations 149 to 162. 

At the most northern (station 149) of these stations 
the convection layer has a thickness of about 50 meters, 
but at station 151 in latitude 12° 40' north the thickness 
is not much greater than 10 meters. Proceeding toward 
the south the thickness again increases more or less 
regularly and at station 160 has a value of about 100 me- 
ters. The highest temperatures at the surface are found 
at stations 150 and 158 to 162. The temperature de- 
creases rapidly with increasing depth below the convec- 
tion layer, and this decrease is especially rapid at sta- 
tions 151 and 152, where all isotherms showing a tem- 
perature of 10° and more are curved toward the surface. 
At stations 151 and 152 we thus find r.n accumulation of 
water of relatively low temperature, but this accumula- 
tion only reaches a depth of about 400 meters. Below 
this depth the highest temperatures are found at stations 
151 and 152 down to a depth of 1000 meters, but at still 
greater depths the temperature maximum wanders to- 
ward the south and at a level of 2500 meters is found 
below station 155 in latitude 4° 51' north. It should be 
noted especially that the isotherm of 5° rises from its 
lowest position more rapidly to the north than to the 
south. The temperature distribution thus shows an ac- 
cumulation of cold water at stations 151 and 152 down to 
a depth of less than 400 meters, and below this depth an 
accumulation of warm water is shown. These accumu- 
lations indicate an ascending vertical movement above a 
level of 400 meters and a descending movement below 
this level. The latter appears to be more pronounced to 
the north than to the south. 

The salinity distribution in this section shows a 
number of remarkable features. At stations 151 and 152 
the surface salinity is below 34.00 per mille and these 
very low values probably must be attributed to the effect 
of precipitation. Both to the north and to the south of 
these two stations the surface salinities are considerably 
higher, but the maximum values are found about 100 me- 
ters below the surface. The subsurface maximum is 
well developed especially to the south of the equator 
where the distribution indicates that at a level of about 
100 meters a considerable transport of water of high sa- 
linity takes place toward the north. At station 150 to the 
north of the equator, we find a slight indication of a sim- 
ilar transport toward the south. The very low surface 
salinities which were observed between stations 159 and 
162 are difficult to explain. It is possible that the flow 
of water of high salinity at a level of 100 meters is inter- 
mittent, and that water of low salinity may reach the sur- 
face in some localities and spread out. It is also possi- 
ble that the water of low salinity, which is found to the 
north of the equator, occasionally spreads toward the 
south. 

Below the layers of high salinity we find a region of 
low salinities between 500 and 1500 meters. To the 
north of station 151 water of low salinity, representing 
the subarctic current, penetrates toward the south. As 
will be shown later, it is probable that the major part of 
this water flows toward the east in the region with which 
we are dealing, but from the section it is evident that 
part of the water continues toward the south. This cur- 
rent divides into two branches, one ascending above a 



level of about 400 meters and the other descending below 
this level. The vertical distribution of the salinity thus 
confirms the conclusions which were drawn from the 
course of the isotherms as to the vertical movement. In 
the most southern part of the section water of a salinity 
below 34.5 per mille penetrates toward the north at a 
level of about 750 meters where the temperature is 5.°5. 
Between stations 151 and 158 we find water of a uniform 
salinity a little below or a little above 34.5 per mille. 

The deep water is again of a uniform character. The 
temperature decreases to values below l.°5 and at sta- 
tion 149 it again increases slightly when approaching 
the bottom. Later we shall discuss the temperature at 
the greatest depths. The salinity of the deep water is 
practically the same within the whole section. 

Turning next to the northern part of the section from 
San Francisco to station 149 we find in this region a thin 
convection layer, which at all stations has a vertical ex- 
tension of less than 50 meters. The lowest surface tem- 
peratures are found off the coast and here the isotherms 
rise rapidly when approaching the coast. This rise, 
however, is found only down to a depth of 400 meters, 
which indicates that an accumulation of cold water is 
confined to the upper layers. The salinities of the upper 
layers are very low in the vicinity of the coast where a 
rapid increase takes place at about 200 meters. In the 
section it appears as if the low salinities, which at 
greater distances from the coast are found at a depth of 
400 meters, form a direct continuation of the low values 
near the surface at the coast. It will b'e shown later on, 
however, that this cannot be the case and that the water 
of low salinity at the coast, and the intermediate water 
at 400 meters belong to distinctly different currents. 

Section Vn. --Section VII (stations 139 to 143) repre- 
sents a north and south section in the central part of the 
Pacific, and follows approximately the meridian of 160° 
between latitudes 34° and 22°. In this section the con- 
vection layer for the most part has a thickness of about 
50 meters, varying from about 40 meters at station 143 
to about 70 meters at station 140. At the last-named 
station the greatest accumulation of warm water is 
found, and the isotherms of the upper layers rise both 
to the north and to the south of the station. At greater 
depths the highest temperatures are found more to the 
north. 

A small accumulation of water of high salinity is 
shown with its center at station 140 where the salinity 
reaches 35.3 per mille at about 200 meters; but the most 
conspicuous feature is represented by the tongue of 
water of salinity below 34.00 per mille extending almost 
to station 140. Even at station 139 a minimum below 
34.1 per mille is found. The axis of the lowest values 
sinks toward the south in the most northern part of the 
section and rises continuously in the southern part. In 
the northern part it follows the isotherm of 6° at a level 
of about 600 meters, but to the south of station 141 the 
axis rises more rapidly than the isotherms and lies at 
a depth of 400 meters at station 139 where the tempera- 
ture is 8°. 

In the deep water both the temperature and the sa- 
linity appear to decrease toward the nofth. The de- 
crease of the temperature is undoubtedly a real feature, 
but the decrease of the salinity toward the north below 
the 2000- meter level is so small that it lies within the 
limits of accuracy of the observations. 

Section XIV. --Section XIV (stations 130 to 140) runs 
from San Francisco to the Hawaiianlslands in a direction 



THE PACIFIC OCEAN 



97 



which changes from southwest to west-southwest. The 
eastern part of this section off the American coast has 
already been discussed because stations 130 to 134 were 
used when construction Section V. 

The convection layer is thin at all the stations of the 
section, remaining, as a rule, thinner than 40 meters. 
Water of a temperature higher than 25° is found directly 
below the surface to the west of station 136. Below the 
warm surface layer the temperature decreases rapidly 
with increasing depth. The isotherm of 10° is met with 
at a depth of almost 400 meters at station 140" it rises 
slowly when approaching the American coast, and direct- 
ly off the coast a rapid rise takes place, indicating an 
accumulation of cold water. 

The low surface salinities off the coast have already 
been discussed. Proceeding toward the west, we find in- 
creasing surface salinities and values above 35.00 per 
mille at stations 137 to 140. The lowest salinities in 
this region are found at a depth of about 400 meters 
where the values lie between 34.00 and 34.1 per mille. 
The axis of the salinity minimum in the western part of 
the section shows minor bends up and down and follows, 
on the whole, the isotherm of 8°, which also oscillates 
up and down in a corresponding manner. The axis rises 
when approaching the coast, and we can regard it as fol- 
lowing practically the same isotherm to the coast if, in 
the region where the salinity decreases with increasing 
depth, we take the value 33.95 per mille as the charac- 
teristic value of this intermediate water. The feature 
which should especially be emphasized is that between 
stations 136 and 140 this intermediate water has a salin- 
ity above 34.00 per mille and a temperature of 8° and is 
found at a level of 400 meters. The rise of the interme- 
diate water as it approaches the coast should also be 
borne in mind. 

The deep water, as previously, shows a nearly uni- 
form temperature which decreases toward the bottom. 
The variations in a horizontal direction are small and 
appear to have an irregular character. The salinity in- 
creases slowly with depth and at the 2000-meter level 
no differences in a horizontal direction are perceptible. 

Section XV. --Section XV (stations 142 to 146) repre- 
sents a very short section which runs east and west in 
approximately latitude 33°. The convection layer again 
has a thickness of less than 40 meters. The isotherms 
are almost horizontal and the temperature decreases to 
less than 10° within the upper 300 or 400 meters. 

The surface salinity is lower than 35.00 per mille at 
all stations except 144, and the salinity decreases with 
increasing depth. In the eastern part of the section sev- 
eral irregularities, intermediate minima and maxima, 
occur which indicate more or less complicated currents. 
A very pronounced salinity minimum with values below 
34.00 per mille is shown at all stations. The axis of the 
lowest value rises considerably from west to east, lying 
at a depth of about 600 meters at station 142 and at a 
depth of 550 meters at station 146. It follows almost 
exactly the isotherm of 7° running slightly below this 
isotherm to the west of station 144 and slightly above 
this isotherm to the east of station 145. 

Comparing the characteristics of this intermediate 
water with those of the corresponding water at stations 
136 to 139 of the preceding section which lies about 10° 
farther south, we find that the layer of water of low sa- 
linity rises toward the south and that the salinity and the 
temperature of this water increase together. In both 
sections we find the intermediate water at a lower level 



when the distance from the American Continent is great- 
est. 

Section VI. - -Section VI, comprising stations 125 to 
130, runs from latitude 51° 58' north, longitude 150° 39' 
west to San Francisco. The convection layer is thin and 
reaches a thickness of more than 50 meters at station 
129 only. The surface temperature increases as one 
proceeds to the southeast, and remains practically con- 
stant from station 128 to the coast. The decrease of 
temperature with increasing depth is rapid in the most 
northern part, especially at station 125 where tempera- 
tures higher than 6° are found above 45 meters only. 
The high surface temperatures in this region appear to 
be the result of heating in summer. On the whole, the 
subsurface temperature increases toward the southeast 
as shown by the sinking of the isotherms in this direc- 
tion. Down to a depth of about 300 meters between sta- 
tions 129 and 130, however, the isotherms rise, indicat- 
ing the accumulation of cold water at the coast. The 
observations at stations 129 and 131, combined with the 
data from station 130, thus reyeal the same features. 
The sinking of the isotherm of 5° is, on the other hand, 
especially rapid between stations 129 and 130, suggesting 
a downward motion of the water at a depth of about 600 
meters. A corresponding divergence of the isotherms 
was found between stations 68 and 71 off the coast of 
South America. 

The surface salinities are very low at all stations, 
being less than 33.00 per mille in the northwestern part 
of the section. A rapid increase takes place at a depth 
of about 150 meters and below this depth the salinity in- 
creases more slowly. It is noteworthy that the increase 
with depth is slow at a level of about 500 meters except 
at the most northwestern stations. The value of the sa- 
linity in the interval having slow increase is between 
33.9 and 34.1 per mille, and the temperature ranges 
from 7° to 3.°5 at station 127, and from 8° to 6° at sta- 
tion 130. It is probable that at this depth we find the 
water, which, in the more southerly sections, represents 
the intermediate water. Between stations 129 and 130 
the isohalines rise at all levels and thus give no indica- 
tion of a downward movement at a level of 500 meters as 
suggested by the course of the isotherms at this layer. 

The deep water appears to be very uniform. The'2° 
isotherm runs practically horizontally at a level of 2000 
meters, and at this depth a uniform salinity of slightly 
more than 34.6 per mille is found. 

After this brief description of the vertical distribu- 
tion of temperature and salinity in the eastern part of the 
North Pacific, we turn to the conditions in the western 
part. 

Section Vin. --Section VIII (stations 94 to 104) runs 
mainly in a southeasterly direction from latitude 20° 12' 
north, longitude 161° 19' east to the Samoan Islands. The 
section thus crosses the equator and, therefore, shows a 
number of features which are similar to those in the 
southern part of Section V. When examining the section 
it must be borne in mind that the northern part runs al- 
most from'east to west and variations which are charac- 
teristic for the north-south direction, therefore, appear 
much exaggerated in our representation. This is evident 
from figures 32 and 33, for instance, in which the obser- 
vations at stations 95 to 104 have been used for the con- 
struction of true north and south sections. 

The convection layer has a thickness of 50 meters 
or more at the northwestern station and reaches almost 
100 meters at station 99. At station 98, which is located 



98 



OBSERVATIONS AND RESULTS IN PHYSICAL OCEANOGRAPHY 



practically at the equator, 0° 18' north, the thickness is 
also very great and may perhaps be taken as almost 150 
meters. South of the equator the thickness is of the or- 
der of 50 meters. 

The surface temperatures are above 25° at all sta- 
tions. The isotherm of 20° runs at approximately the 
same depth at the northern and southern stations, but 
rises toward the surface at station 100. The course of 
the isotherms between stations 102 and 87 is very simi- 
lar to the course of the corresponding isotherms in Sec- 
tion V between stations 150 and 157. Between the levels 
of 150 and 300 meters the lowest temperatures occur at 
station 100, but between 300 and 1500 meters we find the 
highest temperatures at this station. In still greater 
depths the temperature maximum shifts toward the south 
as in Section V. The isotherm of 5° rises more rapidly 
toward the north than toward the south as was the case 
in Section V. 

The distribution of the salinity is also similar in the 
two sections, but in Section VIII it is more symmetrical 
than in Section V. At the surface, values below 34.6 per 
mille are found between stations 101 and 100. From the 
region of low surface salinity values we find increasing 
values both to the northwest and the southeast, but the 
maximum values are found at some distance from the 
surface. The tongues of maximum salinity at a depth of 
about 150 meters indicate a transport of water of high 
salinity toward the equator, whereas the low surface sa- 
linities perhaps can be attributed to a transport of water 
of low salinity away from the region of low salinity to 
the north of the equator. At intermediate depths we find 
a layer of low salinity. The salinity minimum is espe- 
cially well developed to the northwest where the lowest 
values, less than 34.20 per mille, are found at stations 
103 ?.nd 104 at a depth of about 600 meters. The salinity 
increases toward the southeast and the axis of the mini- 
mum values rises in the same direction, following more 
or less the course of the isotherms, but rising more 
rapidly than the latter. The temperature at the level of 
the salinity minimum, therefore, is between 6° and 7° at 
station 104, but about 8° between stations 101 and 102. 
Between stations 100 and 101, the layer of minimum sa- 
linity appears to diverge in two branches, one which 
penetrates almost to the surface at station 100, and one 
which is directed downward. This divergence is not very 
clearly seen in this section but appears better when the 
stations are plotted as if they were lying on a north and 
south line (figs. 32 and 33). A corresponding divergence 
was much more pronounced in Section V. To the south- 
east we find minimum values of the salinity of between 
34.40 and 34.50 per mille at stations 94 to 97. The mini- 
mum is not sharp and the axis of the lowest values, 
therefore, cannot be determined with any great accuracy. 
It appears to lie at a level of about 800 meters, and fol- 
lows the isotherm of 5°. At stations 159 and 162 (Sec- 
tion V) the minimum salinity was found at nearly the 
same level and the temperature was again approximately 
5°. 

The salinity distribution which is shown in this sec- 
tion agrees well with the section which Wiist (1929) has 
constructed for a region farther west, mainly by means 
of observations on the Planet. Wiist' s section extends 
from latitude 15° north to 35° south, and shows especial- 
ly that the current, which at a depth of 150 to 200 meters 
carries water of high salinity toward the equator, sub- 
merges between latitudes 25° and 30°. WQst's section 
reaches to a depth of 600 meters only. Between latitudes 



15° and 10° north the layer of minimum salinity rises 
from 500 meters to about 350 meters and to the south of 
10° north it divides into one ascending and one descend- 
ing branch in agreement with what we have found. The 
salinity minimum to the south of the equator is not shown 
in Wiist's section because it lies at a greater depth. 

The deep water, as usual, is very uniform. The 
temperature decreases to the greatest depth from which 
observations are available, approximately 3000 meters, 
and at this level is highest in the southeastern part of 
the section. The salinity is, on the whole, higher than 
34.60 per mille below a level of about 1700 meters and 
increases with depth as far as the observations go. 

Section Xin. - -Section XIII (stations 101 to 107) in- 
cludes stations 101 to 104, which were used in Section 
VIII, and runs mainly in an east and west direction be- 
tween longitudes 178° and 146° east. The section forms 
a regular curves toward stations 101 and 107, however, 
lying in latitudes 13° 23' and 14° 05' north, respectively, 
whereas station 104 lies in latitude 20° 12' north. This 
curvature toward the north, as presently will be seen, 
determines the characteristic vertical distribution of , 
temperature and salinity which appears in the section. 

The convection layer reaches to at least 50 meters 
at all stations and at some of them has a thickness which 
probably approaches 100 meters. The temperature sec- 
tion shows the greatest accumulation of warm water in 
the central part of the section, but this circumstance 
must be attributed to the fact that the central part lies 
in a higher latitude than the eastern and western parts. 
The downward curvature of the isotherm of 10° is, 
therefore, not related to a change in an east and west 
direction but to a change in a north and south direction. 
The isotherms of 5° and less, on the other hand, have 
their highest position in the central part of the section 
and the curvature of these isotherms must be related to 
to the fact that at greater depths the temperature in- 
creases from north to south. 

The courses of the isohalines show a vertical dis- 
tribution of the salinity, which agrees perfectly with the 
vertical distribution of temperature. The highest sur- 
face value of the salinity is found at the most northern 
station, 104. Below the surface on both sides of this sta- 
tion we find a layer of higher salinity which must be re- 
lated to the subsurface transport of water of high salin- 
ity toward the equator. The intermediate salinity mini- 
mum is most pronounced and is found at the greatest 
depth at station 104. The axis of the minimum values 
rises to both sides, and the values themselves increase. 
The axis rises more toward the southeast and southwest 
than do the isotherms. In the central part the axis lies 
at a depth of 650 meters where the temperature is 6°, 
but at the most southeastern station the minimum is 
found at 450 meters where the temperature is 8.°5, and 
at the most southwestern locality the minimum lies at 
400 meters where the temperature is 9°. The only con- 
clusion which can be drawn as to variations in an east 
and west direction, however, is that the salinity mini- 
mum layer appears to lie higher and the temperature is 
higher at the most western station--107--than at the 
most eastern station- -101. 

It is of interest in this connection to point out that at 
station 149 (Section V), which lies in almost the same 
latitude as station 104, we found a salinity minimum at a 
depth of 350 meters where the temperature was 9°. 
When discussing sections XIV and XV it was shown that 
the minimum layer apparently sinks toward the west and 



THE PACIFIC OCEAN 



99 



this conclusion appears to be verified when one compares 
conditions at stations 104 and 149. 

The deep water is again of a uniform character. The 
temperature decreases and the salinity increases with 
increasing depth as far down as observations have been 
carried out. 

Section IX. --Section IX, comprising stations 107 to 
120, is actually composed of two different sections, one 
running southwest from latitude 47° 02' north and longi- 
tude 166° 20' east to the coast of Japan off Yokohama, 
and one running north and south following practically the 
meridian of 144° east between latitudes 35° and 14° 
north. We shall discuss the latter part of the section 
first. 

The convection layer has a thickness of about 50 
meters at the southern stations of the section, but at the 
northern stations it has a thickness of less than 40 me- 
ters. 

Temperatures above 25° are found at the three 
southern stations only, but the isotherm of 10°, except 
for some undulations, runs almost horizontally at a 
level of approximately 500 meters, but between the two 
most southerly stations it rises distinctly toward the 
south. In this most westerly section we thus find the 
greatest accumulation of warm water in the upper layers, 
but in the deeper layers the temperatures are higher at 
the southern stations. Between 500 and 1000 meters the 
isotherms diverge toward the south. 

The surface salinity has values above 35.00 per 
mille between stations 108 and 109 only. Values above 
35.1 per mille are found between 150 and 200 meters in 
the most southern part of the section, indicating a trans- 
port of water of high salinity from the surface region of 
high salinity located to the northeast. At a depth of 
about 500 meters the isohaline of 34.2 per mille runs 
almost horizontally, undulating up and down, and cor- 
responding to the course of the isotherm of 10°. A con- 
spicuous rise toward the south is found between stations 
107 and 108 corresponding to the rise of the isotherms 
between these stations. The layer of minimum salinity 
can be followed at all stations to the south of station 113. 
Between stations 109 and 113 the axis of the minimum 
value lies at a level of 650 meters where the tempera- 
ture is about 6° and rises to 8.°5 at a depth of 450 me- 
ters at station 107 to the south of station 109. Compar- 
ing these conditions with the corresponding conditions 
in Section VII in the same latitude, we find that the layer 
of minimum salinity probably lies somewhat deeper in 
the most western part of the ocean. 

In the deep water the temperature, which decreases 
very slowly toward the north, decreases with increasing 
depth; and the salinity, which below a level of about 2000 
meters is slightly above 34.6 per mille, increases with 
depth. 

In the northeastern part of Section IX we find a 
quite different stratification. The convection layer is 
very thin, especially at the northeastern stations where 
it perhaps has a thickness of 10 meters only. 

The most conspicuous feature of the vertical dis- 
tribution of temperature is the very rapid change in the 
character of the temperature distribution between sta- 
tions 112 and 116. The isotherms rise rapidly toward 
the north in a manner which reminds one of the rise of 
the isotherms toward the north on the southern side of 
the Grand Banks of Newfoundland in the Atlantic. Be- 
tween stations 115 and 116 we find a "cold wall." The 
change in the temperature distribution, however, appears 



to be of an irregular character and from the course of 
the isotherms, it seems that whirls are formed along 
the boundary between the warm water to the south and 
the cold water to the north. The great temperature con- 
trasts are present down to a level of 500 meters. Below 
this level the contrasts gradually get smaller and at 
1000 meters the temperature difference has been re- 
duced to 1°. At 2000 meters practically nothing is left. 

Between stations 112 and 116 the salinity decreases 
as rapidly as the temperature. The great irregularities 
in the distribution of the salinity strongly support the 
opinion that whirls of great dimensions are formed at 
the boundary between the warm water of high salinity to 
the south and the cold water of low salinity to the north. 
The lowest surface salinities are found at the most 
northeastern stations 119 and 120 where the values are 
below 33.00 per mille. 

The great contrast between the salinities of the up- 
per layers can be followed to a depth of about 500 me- 
ters, but below this level it almost disappears. It is of 
interest in this connection to note that to the north of 
station 116 the isohaline of 34.00 per mille lies at a level 
of approximately 400 meters where the temperature is 
somewhat above or somewhat below 4°. It also is of in- 
terest to note that a downward transport of water, which 
has the same character as the intermediate water of low 
salinity in the southern part of the section, apparently 
takes place only between stations 115 and 116, and that a 
downward transport of such water can hardly be traced 
at the northeastern stations. 

The deep water has the same characteristics as in 
the southern part of the section. Taking the section as a 
whole, we find a tendency toward decreasing tempera- 
ture and decreasing salinity as we proceed toward the 
north at a level of about 2000 meters. 

Section XVI. --Section XVI (stations 118 to 125) runs 
west-southwest from latitude 51° 58' north and longitude 
150° 39' east to 42° 29' north and 155° 24' west. In the 
eastern part the section bends slightly toward the north. 
On a short stretch it runs along the Aleutian Islands and 
continues at last in a southwesterly direction. The con- 
vection layer is very thin at all stations, especially in 
the western part of the section where it is of the order 
of 10 meters only. 

Below the topmost surface layer we find between 
stations 119 and 123 a layer of minimum temperature at 
a level of about 100 meters. At stations 119 and 120 the 
temperature within this layer is below 2° and farther to 
the east values smaller than 3° are found. This water of 
very low temperature probably comes from the Bering 
Sea where it has been formed in the preceding winter 
and from where it has entered the Pacific Ocean, and 
partly spread toward the east. At greater depths the 
temperature decreased regularly as far down as the ob- 
servations were made 

The salinity is very low at the surface and increases 
with depth at all stations except at station 118 where 
some irregularities are found above 200 meters. The 
increase of the salinity is especially rapid down to the 
200-meter level. From there the increase continues at 
a slow rate and the value 34°6 is reached somewhat be- 
low the 2000-meter level. 

It should be pointed out especially that in this sec- 
tion we find no layer of minimum salinity. Furthermore, 
we find no water masses which have the characteristic 
temperature and salinity of the intermediate water in the 
southern sections, namely, 6° and 34 per mille. The 



100 



OBSERVATIONS AND RESULTS IN PHYSICAL OCEANOGRAPHY 



water which has a salinity of 34.00 p'er mille has a tem- 
perature of about 3°, and water having a temperature of 
6° has a salinity which is smaller than 33.5 per mille. 

The deep water is again of a uniform character, but 
appears to be somewhat cooler than the deep w~ter at 
corresponding depths in the equatorial region. Thus the 
isotherm of 2° lies at a depth of about 1700 meters in 
Section XVI, but at the equator it lies at a depth of about 
2300 meters. The salinity of the deep water appears to 
be smaller than in the most northern region; the depth 
of the isohaline, 34.6 per mille, is about 2300 meters in 
Section XVI, but at the equator it is about 1600 meters. 

Distribution of Density 

The horizontal and vertical distributions of density, 
t, have been represented in figures 234 to 245; I-B and 
96, 102, 108, 114, 120, 129, 135, 144, 150, 156, 162, 188, 
174, 180, 189, and 198; I-B, respectively. When prepar- 
ing these the course of the isotherms and isohalines was 
taken into account. We shall not enter into details but 
only draw attention to the most prominent features. 

When examining the figures showing the horizontal 
distribution, it should be borne in mind that at any level 
the movement of the water, relative to the directly under- 
lying water, takes place in such a direction that in the 
Northern Hemisphere one has the light water on the 
right-hand side, and in the Southern Hemisphere the 
light water on the left-hand side. 

Surface. --Here we find the lowest densities on both 
sides of the equator in low latitudes. The beHs of low 
density are separated from each other by a region of 
higher density where, however, the values are only a 
little above the values to the north and to the south. To 
the north of the region of low density in the Northern 
Hemisphere the density increases rapidly with increas- 
ing latitude. This increase is regular except in the re- 
gion off the coast of California and at the coast of Japan. 
In the Southern Hemisphere the density appears to in- 
crease toward the coast of South America and toward the 
south, but within a great area off the coast of South 
America the density remains practically constant. Along 
the coast of Central America the surface density is very 
small within a limited region. 

One hundred-meter level. --At this level the region 
with minimum density to the north of the equator partly 
has been replaced by a region of very high density. To 
the north of latitude 20° north the density increases to- 
ward the north except in the region off the coast of Cali- 
fornia where a rapid increase toward the coast takes 
place, whereas the densities are low off the southern 
coast of Japan. In the Southern Hemisphere the increase 
toward the coast of South America and toward the south 
are the most conspicuous features. The low densities 
along the coast of Central America have disappeared. 

Two hundred-meter level. --Here the development 
has continued in the same direction. The region of max- 
imum density to the north of the equator, however, is 
less pronounced but stretches across the ocean. Two 
regions of minimum density are under development in 
latitudes 20° north and 17° south, and from the former 
there is a general increase toward the north and toward 
the coast of California. The low densities off the south- 
ern coast of Japan are still conspicuous. In the Southern 
Hemisphere the increase of density toward the south is 
more prominent than the increase toward the coast of 
South America. 



Three hundred-meter level .--Here the hig*h densities 
in the equatorial region show a stripe-like distribution. 
The density minimum in latitude 20° north is the domi- 
nant feature in the Northern Hemisphere. A correspond- 
ing minimum is probably developed in the same latitude 
in the Southern Hemisphere, but the observations are 
not extended over a sufficiently wide area to show the 
entire minimum. 

Four hundred- and five hundred-meter levels'. --At 
these levels we find practically the same distribution as 
at the 300-meter level. An area of high density covers 
the equatorial region to almost 20° south and 20° north, 
and the stripe-like distribution is still seen. In the 
Northern Hemisphere the minimum is being displaced 
more and more toward the north. At these levels and at 
the 300-meter level the low density off the southern . 
coast of Japan still prevails. 

Seven hundred-meter ^veL —Here the distribution 
in the Northern Hemisphere is the same as before, ex- 
cept that the minimum has shifted farther north, but in 
the Southern Hemisphere we find a decrease of the den- 
sity toward the south at the most souther'y stations. At 
these stations the direction of the relative current thus 
seems to be reversed. Above the 700-meter level the 
relative current is directed toward the coast; below the 
700- meter level it appears to be directed away from the 
coast. 

One thousand-meter level. -- The differences in den- 
sity have decreased regularly downward and at this ^vel 
are very small, but in the Northern Hemisphere the dis- 
tribution has remained more or less unaltered. In the 
Southern Hemisphere the decrease of the density toward 
the south at the most southern stations is more pro- 
nounced than at the 700-meter level. In latitude 20° 
south we find increasing density toward the south, where- 
as at the higher levels we found decreasing densities. 
The relative current, which at the higher levels was di- 
rected toward the west, appears at this level to be di- 
rected toward the east. 

Fifteen hundred-meter level. --Here the differences 
in density are very small between latitudes 40° south and 
and 40° north, but to the north of 40° north we find, even 
at this level, an increase toward the north. This indi- 
cates a relative movement toward the east as in the up- 
per layers. At the southern stations off South America, 
on the other hand, we still find a decrease toward the south, 
! which indicates relative movement toward the west. 

Two thousand-, twenty-five hundred-, and three 
thousand-meter levels. --Here the density is nearly con- 
stant but the values appear to be lower in the Northern 
than in the Southern Hemisphere. 

We shall not enter on a discussion of the distribution 
of the density in the vertical sections because such a 
discussion would not add materially to the knowledge of 
the character of the different water masses which has 
been obtained by a discussion of the distribution of tem- 
perature and salinity. 

Temperature-Salinity (tS) Relation 

The temperature-salinity diagrams for each station 
in the Pacific are shown in figures 203 to 209; I-B. We 
shall not enter on any detailed discussion of the charac- 
teristic features of these diagrams at the single stations 
but shall make use of the tS relation in order to point out 
the characteristic properties of the water at different 
levels and in different regions. 



THE PACIFIC OCEAN 



101 



For this purpose we have plotted in figures 13 to 18 
all observations below the 100-meter level, using verti- 
cal lines to designate the observations between 100 and 
500 meters, 500 and 1500 meters, and below 1500 me- 
ters. The observations have been combined into groups 
which show the characteristic tS relation within certain 
regions. The limits of these regions have been deter- 
mined by means of the tS curves and may thus be re- 
garded as natural subdivisions. Within each region we 
find, on the whole, the same tf relation at the different 
stations, and in most cases the transition from one type 
of tS relation to another is quite distinct. Cases exist in 
which the transition from one region to another, however, 
takes place within an area which is so great that obser- 
vations at some stations show a tS relation which lies 
between the characteristic relations of the two neighbor- 
ing regions. 

The areas within which the tS relation is nearly the 
same have been indicated in figure 19 in which they have 
been numbered from 1 to 14. Figure 20 shows the tS 
curves for each of these regions. The numbers of the 
regions are entered on the corresponding curves. The 
curves represent the mean curves as derived from the 
diagrams in figures 13 to 18 in which the single obser- 
vations have been entered. From these single diagrams 
it is seen that within every region the water is typically 
stratified. Water of a low temperature is found at great 
depths only, water of a temperature about 3° to 7° be- 
tween the levels 500 and 1500 meters, and water of a 
high temperature is found above 500 meters. It is possi- 
ble, therefore, even on the average curve, to indicate the 
depth interval at which water of certain characteristic 
temperature and salinity is found. This has been accom- 
plished in the average curves on figure 20 by drawing the 
tS curve which shows the characteristic relation below a 
depth of 1500 meters as a very heavy line, the curve be- 
tween 500 and 1500 meters as a moderately thick line, 
and the curve above 500 meters as a thin line. The 
moderately thick line represents water which is found 
between 500 and 1500 meters only, but on the thin line a 
mark has been placed, indicating the maximum stretch 
along the tS curve which represents water below the 500- 
meter level. The part of the thin curve to the right of the 
mark thus represents water which never is found below 
500 meters, whereas the part of the thin curve to the left 
of the mark represents water which may be found both 
above and below the 500-meter level. 

It is not necessary to enter on the characteristic 
properties of the water below 1500 meters within the 
deep areas, because the water is evidently of nearly the 
same character within all areas. From the course of 
the tS curve it is evident that the deep water of the low- 
est temperature has the highest salinity, and also that 
the salinity of water of a temperature of 2° decreases 
from the south toward the north. Distinct differences be- 
between the different areas are found above the 1500- 
meter level and we shall discuss these more fully. 

Region 1 comprises the most southern area of the 
Pacific which was investigated, and lies to the west of 
the South American coast. In this area we find a salinity 
minimum within the interval 500 to 1500 meters which 
is characterized by the corresponding values, S = 34.25 
per mille, t = 5.°2. Above 500 meters we find that water 
of a high temperature has a lower salinity than is found 
at any depth below 500 meters. 

Region 2 lies to the north and northwest of Region 1 
and differs mainly as to the character of the water above 



500 meters. The water between 500 and 1500 meters is 
practically of the same character as in the more southern 
region, but both salinity and temperature appear to have 
increased. The corresponding values at the salinity 
minimum are S = 34.29 per mille and t = 5.°5. 

Regions 3, 4, and 5 lie between south latitudes 10° 
and 20°: Region 3 off the coast of South America, Re- 
gion 4 between longitudes 95° and 130° west, and Region 

5 between longitudes 130° and 175° west. Region 5 ex- 
tends slightly more toward the north than does Region 4. 
In these three regions we find practically the same tS 
relation in the interval, 500 to 1500 meters. The cor- 
responding values at the salinity minimum are: in Re- 
gion 3 S = 34.51 per mille, t = 5.°6; in Region 4 S =34.52 
per mille, t = 5.°6; and in Region 5 S = 34.40 per mille, 

t = 6°0. Above the 500-meter level considerable differ- 
ences exist between these three regions, but we have al- 
ready dealt sufficiently with these differences when de- 
scribing the horizontal and vertical distribution of tem- 
perature and salinity. 

Regions 6 and 7 comprise equatorial areas; one, 
Region 6, off the South American coast, and the other, 
Region 7, in the central part of the Pacific. Below a 
depth of 100 meters we find practically the same tS re- 
lation at stations 150 to 158 and stations 98 to 100 and 
these have, therefore, been combined. It should be noted 
that the northern limit of Region 7, however, does not 
run east and west but approaches the equator more in 
the western than in the eastern part of the ocean. The 
tS relation below the 500-meter level is similar within 
regions 6 and 7, the only difference being that in Region 

6 higher temperatures are found at 1500 meters. The 
lowest salinity values between 500 and 1500 meters are 
about 34.55 per mille and the corresponding tempera- 
ture is 5.°6. 

Regions 8 and 9 stretch together across the Pacific 
in a direction from east-northeast to west-southwest. 
Within these regions we find some differences between 
the tS relation in the eastern and western parts of the 
ocean, but the general features of the relation are simi- 
lar. In the eastern part the salinity decreases more 
rapidly with decreasing temperature and reaches a min- 
imum values of 33.98 per mille where the temperature 
is 8°, but in the western part the decrease of the salin- 
ity is slower and a minimum value of 34.23 per mille is 
reached where the temperature is 9.°5. 

Regions 10 and 11 to the north of regions 8 and 9 
show a similar difference between the relations in the 
eastern and western parts of the ocean. In the eastern 
part the salinity decreases rapidly to a minimum of 

33.97 per mille where the temperature is 6°, whereas 
in the western part a more gradual decrease takes 
place, reaching to a minimum of 34.10 per mille at a 
temperature of 6.°5. 

Region 12 lies off the coast of North America and 
northeast of Region 11. In this region the salinity de- 
creases constantly with decreasing temperature, but 
the decrease is slow where the salinity has a value of 

33.98 per mille and the temperature is 6°, correspond- 
ing to the characteristic temperature and salinity at the 
minimum on the tS curve in Region 11. 

In Region 13, which lies off the coast of Japan in lat- 
itude 40°, and in which only the three stations--115, 116, 
and 117--were occupied, we find a tS relation which is 
rather similar to the relation in regions 10 and 11, but 
with greater variations. The salinity decreases rapidly 
with decreasing temperature to a minimum of 33.78 per 



102 



OBSERVATIONS AND RESULTS IN PHYSICAL OCEANOGRAPHY 



mille at a temperature of 5.°3 and at greater depths 
increases with decreasing temperature. The minimum 
value is found above the 400-meter level, and the cor- 
responding values of temperature and salinity are both 
lower than the corresponding values in Region 11, but 
there they are found below 500 meters. 

In Region 14 to the south of the Aleutian Islands and 
the Bering Sea we find increasing temperature with de- 
creasing salinity up to 500 meters, but above this level 
the temperature remains constant at about 3.°4, whereas 
the salinity decreases. 

It is seen that the tS curves in regions 1 and 2 and 
regions 10 and 11 have nearly the same form except in 
Region 1 near the surface. The stratification is thus of 
a similar character in the North and South Pacific. The 
transition from the tS curve in about latitudes 40° south 
and 40° north to the tS curves of the equatorial region is 
more or less similar in both hemispheres. 

The Intermediate Water 

The most conspicuous feature which is revealed by 
the curves is the existence of water of low salinity at an 
intermediate depth. In the Southern Hemisphere the in- 
termediate water of the Pacific Ocean is probably being 
formed in the same manner as the corresponding inter- 
mediate water of the Atlantic and Indian oceans; it sinks 
and flows north from the region of the Antarctic conver- 
gence, which has been traced all the way around the 
Antarctic Continent. 

If the Antarctic intermediate water follows a more 
or less direct course from the region where it sub- 
merges to the regions in which we have found it, we 
must assume that the water has a high oxygen content. 
Fortunately the oxygen content has been observed at two 
of the Carnegie stations in regions 1 and 2, namely at 
stations 52 and 57. At station 52 the observations show 
a maximum of oxygen, 5.09 ml/L, at a depth of 657 me- 
ters where the intermediate water was found. At sta- 
tion 57 observations are lacking for the central part of 
the intermediate water but at the upper part of this 
water, at a depth of 468 meters, the oxygen content 
showed a maximum of 5.47 ml/L. Thus, the intermedi- 
ate water appears to have a high oxygen content in con- 
trast with the corresponding water in the Northern 
Hemisphere. This high content strongly supports the 
opinion that the water comes on a direct route from a 
region where it has been in contact with the atmosphere. 

In the Northern Hemisphere a convergence, corre- 
sponding to the Antarctic convergence, is not found, but 
we have seen, when studying Section IX, that big whirls 
are formed along the boundary of the warm and the cold 
water off the Japanese coast, and it was pointed out that 
within these whirls water of the typical properties of the 
intermediate water was found. In this region probably 
we must look for one of the places where a supply of 
water to the intermediate current takes place. It is 
possible that the region where such whirls are formed 
extends to some distance from the Japanese coast, but 
this extension cannot be very great, considering the 
general character of the currents. The water which is 
supplied to the intermediate current should thus be 
formed by mixing of different water masses in the re- 
gion off Japan, but this mixing takes place below the 
surface, judging from the conditions which are repre- 
sented in Section IX. 

The mixing appears to take place between water of 



low temperature and low salinity coming from the north, 
perhaps from the upper layers, and warmer water of 
higher salinity which is carried from the south by sub- 
surface currents. Therefore, part of the water which 
supplies the intermediate current has not been in direct 
contact with the atmosphere and must consequently con- 
tain a relatively small amount of oxygen. Such process- 
es would explain the fact that the oxygen content of the 
intermediate water in Region 11 is of the order of be- 
tween 2 and 4 ml/L. In this region the oxygen content of 
the intermediate water generally decreases with in- 
creasing depth, but a secondary maximum between 300 
and 400 meters at stations north of latitude 20° north in 
indicates an admixture of surface water. 

The Deep Water 

Temperature and salinity. --When discussing the 
horizontal and vertical distribution of temperature and 
salinity, we pointed out that the deep water is of a very 
uniform character. The temperature lies between l.°5 
and 2°, and the corrected salinity between 34.65 2nd 
34.73 per mille. Our horizontal representations went 
down to a level of 3000 meters. It is of interest to ex- 
amine the few observations which are available for 
greater depths. At several stations observations with 
intervals of about 500 meters were taken below the 3000- 
meter level. At a great number of stations the tempera- 
ture at the bottom was measured, but in these cases no 
water samples were obtained for determining the salin- 
ity. 

Table 9 gives the mean temperatures and salinities 
within the regions into which the ocean was divided on 
the basis of the tS relations. The mean values have been 
computed for the intervals 3000 to 3500, 3500 to 40Q0, 
4000 to 4500, and below 4500 meters. From the last in- 
terval only temperature observations are available, and 
from the interval 4000 to 4500 meters salinity observa- 
tions are present from regions 4 and 6 only. 

It is seen that the temperature is very uniform in 
the great depths of the North Pacific where the greatest 
difference between any of the mean values from the dif- 
ferent depths and different regions amounts to only 0.°24. 
The temperature appears to increase slightly toward the 
bottom within some of the regions and later we shall re- 
turn to this feature. 

In the South Pacific we find, on the other hand, con- 
siderable variations both in a horizontal direction and 
with depth. The highest temperature is found in Region 
6 near the equator off the coast of South America and off 
the coast of Peru where the temperature is constant 
between 3000 and 4000 meters. In Region 5 in the cen- 
tral part of the Pacific in latitude 15° south and in the 
most southern region--l--the temperature decreases 
with increasing depth. 

The salinity appears to decrease from the Southern 
to the Northern Hemisphere but within each region the 
variations in a vertical direction are so small that they 
are within the limits of the accuracy of the observations. 
The values in the table should probably be increased by 
0.03 per mille (see p. 72). 

Bottom temperature. --The bottom temperatures at 
depths greater than 3000 meters have been entered in 
table 10 and figure 21. The values underscored in the 
figure refer to depths between 3000 and 4000 meters. In 
the South Pacific high bottom temperatures are found in 
the eastern part but here no observations from depths 



THE PACIFIC OCEAN 



103 



Table 9. Temperatures and salinities below 3000 meters in stated regions and intervals of depth 



Depf 


h in 
ers 


Region 


mel 


1 


2 


3 


4 


5 


6 


7 


8 ; 


9 


10 


11 


12 13 


1 14 


3000 
3500 
4000 


-3500 

-4000 

-4500 

4500 


1.52 
1.23 


1.86 


1.82 
1.82 


1.83 
1.57 


1.66 
1.51 
1.33 
1.21 


2.09 


Temperature °C 
1.59 1.68 
1.46 

1.44 


1.55 
1.52 
1.55 
1.52 


1.55 
1.46 

1.49 


1.54 
1.51 
1.53 
1.61 


1.58 
1.56 


1.57 


3000 
3500 
4000 


-3500 
-4000 
-4500 


34.68 
34.65 




34.67 
34.68 


34.67 


34.66 
34.66 


34.62 


Salinity 
34.66 
34.64 


%o * 
34.64 


34.64 
34.64 
34.64 


34.62 
34.63 


34.62 
34.65 
34.65 




34.63 



♦Values probably 0.03 °/oo too low. 



greater than 4000 meters are available. The lowest 
bottom temperatures are found to the south of the equa- 
tor at stations 160 and 161 in about latitude 13° and lon- 
gitude 167°. The values of temperature at these stations 
are If 09 and If 08 at the depths < 4444 meters and 5084 
meters respectively. Between the equator and latitude 
20°, and in longitude 140° west, the bottom temperatures 
lie between If 4 and If 5, but to the north of latitude 20° 
we find values above If 5 in the entire region except at 
two stations off the coast of Japan, where lower temper- 
atures are found. At two stations--141 and 142--to the 
northwest of the Hawaiian Islands, temperatures are 
above If 6, but other than these exceptions the bottom 
temperatures appear to be very uniform. 

When discussing the mean temperatures at different 
depths and within different regions, we pointed out that 
the temperature increases with depth in some regions. 
Examining the data from the single stations, we find only 
four stations at which a decided increase of temperature 
with depth takes place, namely, stations 37, 135, 142, 
and 146. 

Table 11 gives the observed temperatures at these 
stations, the potential temperatures (see p. 32) the sa- 
linities, and the oxygen content. Station 37 is located off 
the coast of Central America, and here the increase of 
temperature with the depth is so considerable that the 
potential temperature is constant. The decrease of the 
salinity from 34.65 per mille (34.68) at 2730 meters to 
34.63 per mille (34.66) at 3231 meters is so small that 
we cannot give any weight to this difference. We must 
assume that the salinity is constant, and the constant 
potential temperature then indicates that indifferent 
equilibrium exists below a level of 2700 meters. 

Stations 135, 142, and 146 are all taken in nearly the 
same region. At these stations the temperature in- 
creases with depth, but the potential temperature de- 
creases and at the same depth is very nearly the same 
at the different stations. The salinity, on the other hand, 
appears to be constant. The variations must be ascribed 
to accidental errors of observation because, combining 
observations from five stations in this region, we find 
the salinities 34.638 (34.668), 34.650 (34.680), and 34.644 
(34.674) per mille at the depths 3100, 3700, and 4100 
meters, respectively; that is, practically no variation 
with depth. The equilibrium must, therefore, be stable. 
At a few other stations in this same region we find an 
indication of a temperature minimum at a depth of 3700 
meters, but the increase below this level is smaller than 
Of 05 and therefore the stratification is still more stable 
at these stations. Helland-Hansen (1930) has shown that 



Table 10. Bottom temperatures of water, bottom 

depths greater than 3000 meters, 

Pacific Ocean, Carnegie, 1929 



Station 



Lati- 
tude 



Longi- 
tude 
West 



Depth 



Ther- 
mom- 
eter 



Bot- 
tom 



Tem- 
per - 
ture 



49 


° / 

23 16 S 


114 45 


3098 


3098 


°C 
1.86 


76 


15 18 S 


97 28 


3181 


3197 


1.84 


82 


14 52 S 


126 07 


3596 


3631 


1.57 


83 


17 00 S 


129 45 


3921 


3966 


1.55 


84 


17 11 S 


133 18 


4076 


4121 


1.51 


85 


17 12 S 


136 37 


3746 


3791 


1.53 


87 


18 05 S 


145 33 


4270 


4315 


1.40 


110 


26 20 N 


215 36 


2996 


3036 


1.49 


111 


31 00 N 


215 44 


5978 


6008 


1.49 


112 


33 51 N 


218 45 


3901 


3931 


1.41 


115 


37 40 N 


214 34 


5360 


5396 


1.55 


116 


38 41 N 


212 19 


5513 


5545 


1.53 


117 


40 20 N 


209 02 


5261 


5296 


1.56 


119 


45 24 N 


200 24 


5170 


5198 


1.54 


127 


44 16 N 


137 37 


4004 


4026 


1.56 


128 


40 37 N 


132 23 


3796 


3806 


1.58 


131 


33 49 N 


126 20 


4388 


4418 


1.55 


132 


31 38 N 


128 48 


4221 


4251 


1.55 


133 


29 21 N 


132 30 


4396 


4426 


1.57 


134 


27 45 N 


135 22 


4498 


4528 


1.58 


135 


26 39 N 


139 07 


4660 


4695 


1.56 


137 


24 02 N 


145 33 


5268 


5208 


1.52 


138 


22 53 N 


151 15 


5342 


5382 


1.52 


139 


21 47 N 


155 31 


4990 


5030 


1.49 


140 


23 26 N 


159 27 


4722 


4762 


1.55 


141 


29 02 N 


161 11 


5627 


5667 


1.63 


142 


32 42 N 


160 44 


5747 


5787 


1.65 


146 


31 51 N 


140 50 


4716 


4756 


1.55 


148 


24 57 N 


137 44 


4795 


4835 


1.50 


149 


21 18 N 


138 36 


5280 


5320 


1.53 


150 


16 15 N 


137 06 


4513 


4553 


1.44 


151 


12 40 N 


137 32 


4878 


4918 


1.49 


155 


4 51 N 


146 46 


5273 


5304 


1.44 


156 


3 01 N 


149 46 


4913 


4953 


1.39 


159 


9 24 S 


159 01 


5505 


5545 


1.34 


161 


12 04 S 


164 57 


4444 


4484 


1.09 


162 


13 36 S 


168 23 


5084 


5124 


1.08 



in the eastern North Atlantic the potential temperature 
is constant below a level of 4000 meters, whereas in the 
western North Atlantic it decreases toward the bottom. 



104 



OBSERVATIONS AND RESULTS IN PHYSICAL OCEANOGRAPHY 



A constant potential temperature over a wide area is 
generally attributed to the influence of heating from be- 
low, from the interior of the earth, and it is assumed 
that the horizontal currents must be very slow where a 
constant potential temperature can be developed. Exam- 
ples of a constant or even a downward increasing poten- 
tial temperature are known from the deep basins in the 
region of the East Indian Islands, and here one probably 
finds stagnating water in the great depths. The fact that 
the potential temperature appears to decrease toward 
the bottom in the North Pacific indicates that the bottom 
water is not stagnating but is being renewed. The rela- 
tively high oxygen content and the increase of this con- 
tent toward the bottom strongly support the opinion that 
a renewal of the bottom water by horizontal transport 
takes place. The low bottom temperatures in the South 
Pacific point toward a more rapid renewal of the bottom 
water in this part of the Pacific. No oxygen observations 
are available from these stations and therefore we are 
unable to obtain a verification of our conclusions. 

The origin of the deep water of the Pacific has been 
discussed previously (Sverdrup, 1931). It was pointed 
out that the deep water cannot be formed by the sinking 
of surface water in the central part of the ocean (com- 
bined with processes of mixing) because the deep water 
is separated from the surface water by a layer of mini- 
mum salinity. It was also shown that the deep water 
could not be formed in the neighborhood of the Antarctic 
Continent because the temperatures are too high. We 
may add that, for the same reason, the deep water can- 
not come from the Bering Sea. Furthermore, it is not 
probable that bottom water of low temperature is formed 
in the Bering Sea by the processes which have been de- 
scribed by Nansen, because the surface salinities in the 
Bering Sea appear to be too low, if we judge from the 
salinity of the surface current which enters the Pacific 
Ocean. 

The available data strongly point in the direction 
that water of the same type as the deep water of the Pa- 
cific is formed in the eastern part of the Indian Antarc- 
tic Ocean and that the origin of the deep water of the 
Pacific has to be sought there. In order to explain this 
formation, it was assumed that Antarctic bottom water 

Table 11. Stations at which a decided temperature 
increase toward the bottom was observed. 





Depth 


Temperature 


Salin- 
ity* 
%o 


Oxygen 


Station 


Bottom 


Obs'n. 


Obs'd. 


Poten. 


content 




meters 


meters 


°C 


°C 


ml/L 


37 


3324 


2730 


2.05 


1.84 


34.65 








3231 


2.10 


1.84 


34.63 








3324 


2.12 


1.85 






135 


4695 


3301 


1.52 


1.26 


34.64 


2.92 






3736 


1.51 


1.21 


34.65 


3.11 






4098 


1.53 


1.19 


34.63 


3.15 






4660 


1.56 


1.15 






142 


5787 


3268 


1.54 


1.28 


34.60 


2.83 






3682 


1.52 


1.22 


34.64 


3.23 






4043 


1.53 


1.19 


34.62 


3.29 






5747 


1.65 


1.09 






146 


4756 


3159 


1.54 


1.31 


34.65 


2.23 






3610 


1.50 


1.21 


34.66 


3.11 






4069 


1.51 


1.17 


34.65 


3.11 






4486 


1.55 


1.16 


34.65 


3.40 






4716 


1.55 


1.13 







♦Values probably 0.03 °/oo too low. 



of low temperature and relatively high salinity was 
formed everywhere on the continental shelf of the Ant- 
arctic Continent. This water would sink to great depths 
and contribute toward the formation of cold bottom water 
which would tend to spread toward the north but, owing 
to the rotation of the earth, would be deflected to the left 
and flow along the continent from east to west. A com- 
plete circumpolar flow would, however, not be developed 
since the submarine ridge between South America and 
the Antarctic Continent would present a serious obstacle 
to a flow of the bottom water toward the west. In the re- 
gion of the Weddell Sea the bottom water, therefore, 
would be deflected toward the north and a great part of 
this water would enter the western basin of the South 
Atlantic Ocean. Furthermore, it was assumed that this 
inflow of cold bottom water was in part responsible for 
the outflow from the Atlantic of warmer and more saline 
deep water at some higher level. This flow of Atlantic 
deep water must also be deflected toward the left which, 
in this case, means to the east, and the Atlantic deep 
water must, therefore, enter the Indian Ocean as pointed 
out by L. Moller (1929) and clearly demonstrated by 
Wiist (1935). In the Antarctic Ocean to the south of the 
Atlantic and the Indian oceans, mixing between these two 
types of water, the cold Antarctic bottom water and the 
warmer Atlantic deep water, must take place and, as a 
result of these processes of mixing, a water type is 
formed which is similar to the deep water of the Pacific. 
It was assumed that this water enters tthe Pacific 
through the passage between New Zealand and the Ant- 
arctic Continent. 

This hypothesis concerning the formation of the deep 
water of the Pacific was advanced at a time when no re- 
liable deep-sea observations were available from the 
vicinity of the Antarctic Continent except in the Weddell 
Sea area. Since that tine a considerable amount of 
oceanographic work has been carried out on the expedi- 
tions with Discovery II , on the British Australian New 
Zealand Antarctic expeditions conducted by Sir Douglas 
Mawson, and on the Norwegian expeditions organized by 
Mr. L. Christensen. The observations from these vari- 
ous expeditions have not yet been published, 1 but the 
writer has had opportunity to examine the results from 
the British Australian New Zealand Antarctic expedition 
and to become acquainted with results from L. Christen- 
sen's cruises. The new information necessitates con- 
siderable modification of the views which were present- 
ed in 1931 but the most important conclusion, that the 
deep water of the Pacific Ocean is formed in the Antarc- 
tic Ocean and enters through the passage between New 
Zealand and the Antarctic Continent, remains unaltered. 

It is now evident that a considerable formation of 
Antarctic bottom water takes place only within the area 
of the Weddell Sea. H. Mosby (1934) has shown that the 
bottom water in the Weddell Sea is formed by mixing of 
deep water (temperature about 1° C and salinity about 
34.70 per mille) and water from the continental shelf 
which has been cooled to freezing point (about -If 85 C ) 
and which has attained a salinity of about 34.60 per 
mille, owing to the processes of freezing. The result- 
ing bottom water has a temperature of about -0.°6 C and 

*The observations in physical oceanography in the 
British Australian New Zealand Antarctic expedition 
have been published by A. Howard (1940) and have been 
discussed by H. U. Sverdrup (1940). 



THE PACIFIC OCEAN 



105 



a salinity of about 34.66 per mille, and it shows a high 
oxygen content since the water on the shelf is nearly 
saturated with oxygen. Along the Antarctic coast of the 
Weddell Sea the flow of the water is directed toward the 
west and the westward motion of the waters can be 
traced as far east as the region of Enderby Land. This 
westward flow represents the southern part of a big eddy 
which characterizes the entire Weddell Sea region. 

The observations from the Australian Antarctic ex- 
peditions and from L. Christensen's expedition with the 
Thorshavn show that sinking of water from the continen- 
tal shelf does not contribute materially to formation of 
bottom water within the entire region from Enderby Land 
and eastward to Drake Passage and they show, further- 
more, that the flow of the deep water is directed toward 
the east within the entire region. From observations at 
a few stations it is evident that water from the shelf in- 
termittently sinks to great depths but in small quantities 
only, for which reason the character of the bottom water 
is only slightly influenced by these processes. The 
previous hypothesis of the writer, that bottom water was 
formed all around the Antarctic Continent and that a flow 
of bottom water toward the west took place in every re- 
gion, must therefore be abandoned. It is probable that 
the surface waters near the continent flow toward the 
west, but within the deep water there evidently exists an 
Antarctic circumpolar current which flows toward the 
east and follows the continent (except in the region of the 
Weddell Sea) as far east as Enderby Land, where a big 
eddy occurs on the southern side of the circumpolar cur- 
rent. 

The characteristic properties of the water masses 
within this circumpolar current are mainly determined 
by the deep-water flow in the Atlantic Ocean, including 
the Weddell Sea area. The deep-water flow within the 
Atlantic Ocean has recently been discussed by Wiist 
(1935) who has shown that three areas exist within which 
the surface waters attain such a high density that they 
must sink and contribute to the renewal of characteristic 
water masses at great depths. One of these areas is 
represented by the Mediterranean. Water of very high 
salinity flowing out from the Mediterranean mixes with 
Atlantic water and spreads toward the north and the 
south, where it can be traced as an upper deep water. A 
second area is found in the waters between Iceland, 
Greenland, and Labrador. Within this area Atlantic 
water of relatively high salinity is mixed with Arctic 
water and cooled to such a low temperature that in some 
localities water is formed which is of uniform density 
from the upper layers to the bottom. Here water from 
the upper layers may sink to great depth and contribute 
to the renewal of the Atlantic lower deep water (mittleres 
Tiefenwasser, according to Wiist's terminology) which 
can be traced to latitude 55° south. Within this region 
or farther north, conditions may favor the development 
of a water of lower temperature and lead to formation of 
the bottom water of the North Atlantic, but this type of 
water does not spread to any considerable distance and 
is, therefore, of minor importance. The third area is 
within the Weddell Sea, where the Antarctic bottom 
water is being formed in the manner which has been de- 
scribed. This bottom water spreads toward the north 
and can be traced to latitude 40° north. 

Within the Atlantic Ocean we find, therefore, an 
"active" deep-water circulation, especially between the 
sea to the south of Greenland where the Atlantic lower 
deep water is formed, and the area of the Weddell Sea 



where the Antarctic bottom water originates. No such 
"active" deep water circulation is present in the other 
oceans. In the Indian Ocean water from the Red Sea 
spreads at moderate depths, but is of much less impor- 
tance than the Mediterranean water in the Atlantic. 
Water corresponding to the Atlantic lower deep water is 
not formed in the Indian Ocean nor is Antarctic bottom 
water formed south of the Indian Ocean. Within the en- 
tire area of the Pacific Ocean no renewal of any type of 
deep water takes place. 

The water masses of the Antarctic circumpolar cur- 
rent are, as already mentioned, formed by mixing of 
Atlantic deep water and Antarctic bottom water. Wiist 
has shown that such processes of mixing take place to a 
great extent in the Atlantic Ocean, and he has computed 
the percentage amount of true Atlantic deep water or 
true Antarctic bottom water in the layers of the Atlantic 
Ocean. The two types of water are still characteristi- 
cally different within the circumpolar current in the 
southern part of the Atlantic Ocean, but when carried 
toward the east by this current the differences disappear, 
owing to processes of mixing, and to the south of Aus- 
tralia we find water of a very homogeneous character 
which can be described as a special type of water, the 
Antarctic circumpolar water. The temperature of this 
water lies between 0° and 2° and the salinity between 
34.68 and 34.74 per mille. 

This water flows, as already stated, around the en- 
tire Antarctic Continent and follows the continental slope 
except in the region of the Weddell Sea where there is a 
large eddy south of the circumpolar current. This is 
evident from the observations of the Australian Antarc- 
tic expedition, and Clowes (1933) has convincingly shown 
that the flow through Drake Passage is directed from the 
Pacific to the Atlantic Ocean. Accurate determinations 
of the oxygen content within the circumpolar current 
might confirm this conclusion. From the Meteor obser- 
vations (in 1926) Wiist finds in the Weddell Sea region an 
oxygen content of 4.6 ml/L at a temperature of l.°6, and 
of 5.6 ml/L at a temperature of -0.°6. The oxygen ob- 
servations on the Australian Antarctic expedition and 
L. Christensen's expedition with Thorshavn, and obser- 
vations from the Drake Passage on board Discovery II 
in 1931 indicate a decrease of the oxygen content of the 
deep water from the region north of the Weddell Sea and 
eastward to Drake Passage. Within the Antarctic cir- 
cumpolar water, the oxygen content increases toward the 
bottom and the temperature decreases. Thus, a relation 
exists between the oxygen content and the temperature 
and, on an average, the oxygen content is nearly a linear 
function of the temperature. 

In the Weddell Sea region (1926) 

02 = [4.42 + 0.45(2°-t)]ml/L 
In the Indian Antarctic Ocean (1929-1930) 

02 = [4.18 + 0.50(2°-t)]ml/L 
In the Drake Passage (1931) 

2 = [3.95 + 0.45(2°-t)]ml/L 

The Meteor observations in the Drake Passage in 1926, 
however, show very nearly the same oxygen content as 
the water of similar temperature and salinity to the 
north of the Weddell Sea. 
Drake Passage (1926) 2 = [4.35 + 0.45(2°-t)]ml/L 

Thus, the evidence is conflicting and at present it can 
only be stated that a majority of observations indicate a 
decrease of the oxygen content of the deep water in an 



106 



OBSERVATIONS AND RESULTS IN PHYSICAL OCEANOGRAPHY 



eastward direction from the Weddell Sea to the Drake 
Passage, as would be expected if the flow is directed to 
the east, but this feature needs to be confirmed. It may 
be added that great variations may occur, owing to vari- 
ations in the admixture of water from the shelf, and such 
variations may be responsible for the different condi- 
tions in different years. 

The deep water of the Pacific is, as already stated, 
similar to the deep water of the Antarctic circumpolar 
current, which is characterized by temperature between 
0° and 2°, and by salinity between 34.68 and 34.74 per 
mille. From table 9 it is seen that below 3000 meters 
the temperature lies between l.°2 and l.°9, if we disre- 
gard Region 6 off Central America. The observed sa- 
linity lies between the limits 34.62 and 34.68 per mille, 
but the values are probably consistently about 0.03 per 
mille too low, and the actual range is therefore 34.65 to 
34.71 per mille, in good agreement with the salinity of 
the circumpolar waters. The highest salinities (cor- 
rected values greater than 34.7) are found in the South 
Pacific where, according to the few available data, the 
oxygen content of the deep water appears to be relative- 
ly high. These features indicate that the deep water of 
the South Pacific is slowly renewed by addition of water 
from the circumpolar current. Whether this renewal 
has the character of the regular inflow in some definite 
region or takes place by irregular processes of mixture 
cannot be decided by means of the available data. 

In the North Pacific the salinity of the deep water is 
slightly lower, and the oxygen content considerably low- 
er. These features indicate that the renewal of the deep 
water of the North Pacific by admixture of water from 
the Antarctic region is much slower than in the South 
Pacific, *and, furthermore, it must be assumed that slow 
admixture of intermediate water of low salinity takes 
place and reduces the salt content of the deep water. 

The information which is now available strongly 
points in the direction that no definite flow of deep water 
exists in the Pacific Ocean a/id that the renewal of the 
water is a result of slow and irregular processes of 
mixing. It cannot be doubted, however, that on an aver- 
age a transport of deep water takes place from south to 
north. It is possible that this transport takes place 
principally along the bottom, and that an outflow of deep 
water from the Pacific is present at some high level. It 
is also possible that the outflow from the Pacific takes 
place within the upper layers and that slow descending 
motion of the deep water occurs in certain regions. 



C ur r ents 

Surface Currents 

On several occasions we have touched on the prob- 
lem of the circulation of the waters in the Pacific and 
especially have discussed to some extent the intermedi- 
ate currents in the South and the North Pacific. We shall 
now undertake a more detailed discussion of the circula- 
tion as far as this is possible by means of the Carnegie 
data. The discussion will be based principally on the 
charts showing the topography of the isobaric surfaces 
0, 100, 200, 300, 400, 500, 700, 1000, and 1500 decibars 
relative to the topography of the 2000-decibar surface. 
In these charts, lines of equal relative elevation have 
been drawn, except off the coast of Japan where the con- 
ditions are too complicated to be represented by the few 
observations of the Carnegie in this region. Near the 



equator the course of the lines is also very doubtful for 
reasons which will be explained when dealing with the 
Equatorial Counter current. 

The charts represent very nearly the absolute to- 
pography of the different isobaric surfaces because it 
can be assumed, on account of the uniform character of 
the deep water, that the 2000-decibar surface is very 
nearly horizontal. It must be borne in mind, however, 
that when constructing the charts we combined the data 
from stations which in some regions were taken at great 
intervals of time. This combination may lead to appar- 
ent irregularities, especially in regions where the cur- 
rent systems undergo considerable displacement. Fur- 
thermore, it must be emphasized that from our repre- 
sentations we can draw conclusions only as to the cur- 
rents which are maintained by the distribution of densi- 
ty. The distribution of density is partly maintained by 
the processes of heating and cooling, evaporation and 
precipitation, and partly by the effect of the prevailing 
winds on the surface layers. 

It is clear that differences in heating and cooling in 
the different latitudes, and differences in evaporation 
and precipitation, create differences in density which 
maintain a system of currents independently of the ac- 
tion of external forces such as the tangential force ex- 
erted by the prevailing wind. On the other hand, it is 
not self-evident that the prevailing winds influence the 
distribution of density in such a manner that part of the 
effect of the winds is included in the currents which are 
computed on the basis of the distribution of density, but 
some evidence that such is the case can be found. 

Figure 22 shows the currents at the surface, sup- 
posing the water at a depth of about 2000 meters to be at 
rest, and supposing that the velocity, v, of the currents 
can be derived from the map representing the topog- 
raphy of the surface by means of the formula 

v = (l/L)(c/sin <t>) 

where L is the distance between two lines of equal dy- 
namic height (anomaly), and $ is the geographic latitude, 
and c is a constant. The current is directed at right 
angles to the gradient of the isobaric surface, that is, 
parallel to the lines of equal dynamic height. In the 
Northern Hemisphere it is directed 90° to the right of 
the gradient, in the Southern Hemisphere 90° to the left. 

This computation probably gives velocities which 
are too great in the vicinity of the equator because the 
friction, which is not considered, probably plays a great- 
er part in this region. Aside from these restrictions 
the computed surf-ace currents represent the currents 
which result from the distribution of density between the 
surface and a depth of about 2000 meters. 

This map of the surface currents will now be com- 
pared with the map of the surface currents (figure 23) 
constructed by Merz and published by Wiist (1929). The 
latter map is based on the observed surface currents as 
obtained by dead reckoning and astronomic observations 
oi^ board ship, and thus represents the actual currents 
as resulting from the combined effect of the prevailing 
winds and the distribution of density. The agreement 
between the two maps is remarkable, considering the 
widely differing material on which they are based. Some 
discrepancies are found in the northern part of the North 
Pacific, but it may be noted that: 

1. The line separating the easterly and westerly 
currents in the North Pacific in figure 22 lies near the 
line of subtropic convergence as shown by Merz. 



THE PACIFIC OCEAN 



107 



2. The convergence in latitude about 40° north off 
the coast of Japan in the figure corresponds to the west- 
ern part of the northern polar front as shown by Merz. 

3. The westerly current in the inner part of the 
Gulf of Alaska is seen in both maps. 

4. The Equatorial Countercurrent runs in nearly the 
same regions on the two maps. 

5. The line separating the westerly and easterly 
currents in the eastern part of the South Pacific practi- 
cally coincides with the corresponding line of subtropic 
convergence as shown by Merz. 

It is hardly a coincidence that the surface currents, 
which are derived from dynamic computations, agree 
with the observed surface currents, in spite of the fact 
that the latter result from the combined effect of the 
wind and the primary distribution of density. This 
agreement must be interpreted as indicating that the ef- 
fect of the wind is to maintain a certain distribution of 
density, and the computation of the currents on the basis 
of the density distribution actually includes part of the 
effect of the prevailing winds. 

Palmen (1930) has recently discussed a number of 
observations from the Gulf of Bothnia which demonstrate 
in a striking way the effect of the wind on the distribu- 
tion of density. When the wind blows in the direction of 
the Gulf the light water is accumulated along the right- 
hand shore and the heavy water along the left-hand shore 
The current, which is computed from this distribution of 
density (the convection current according to Ekman's 
terminology) has a velocity corresponding to the velocity 
of the wind current which would be produced under the 
given circumstances. This example deals with conditions 
in a narrow bay, but it is probable that the results are of 
general importance and that even in the open ocean we 
may find that the wind changes the distribution of density 
in a corresponding manner. This would mean that a 
prevailing wind maintains an abnormal distribution of 
density. If the wind should stop blowing, the normal dis- 
tribution of density would be re-established, and the 
dynamic computation would give the current which would 
be present if the tangential force exerted by the wind on 
the surface were absent. Supposing these considerations 
to be correct, we may regard our dynamic charts as 
representing the total currents resulting from the dif- 
ferences in density which would occur in the absence of 
wind, and from the abnormal distribution of density 
which is established and maintained by the action of the 
wind. 

As to the character of the wind current we remind 
the reader of Ekman's theory. According to this the 
total transport of water is directed 90° to the right of 
the direction of the wind in the Northern Hemisphere, 
and 90° to the left in the Southern Hemisphere. The 
depth to which the wind current reaches depends on the 
latitude and on the eddy viscosity, which again is a func- 
tion of the stratification of the water. 

In general, it is assumed that at some distance from 
the equator the wind currents reach to less than 100 me- 
ters in depth, but the effect on the distribution of density 
must reach much deeper. Since the surface water is 
light, a transport of surface water to the right of the di- 
rection of the wind leads to an accumulation of light 
water on the right-hand side of the wind, and on the left- 
hand side the light surface water must be replaced by 
heavier water from greater depths. On the right-hand 
side of the wind the surfaces of equal density are de- 
pressed, and on the left-hand side they are raised. The 



effect may reach to considerable depths and, owing to 
this "abnormal" distribution of density, a current in the 
direction of the wind is created. 

In the open ocean the maintenance of an abnormal 
distribution of density represents only part of the effect 
of the wind. If it represented the total effect, the condi- 
tion 

dv' 



dv/ 



(" 



dz 



V 



would have to be fulfilled. Here v is the coefficient of 
eddy viscosity, v x and Vy, the components of the convec- 
tion current, and T x ana Ty, the components of the tan- 
gential stress of the wind. This condition, which may 
be satisfied in a narrow channel, is never fulfilled in 
the open ocean, since a decrease of the required magni- 
tudes of the velocity near the surface does not occur. 
Pure drift currents will, therefore, be present beside 
the convection current, but under stationary conditions 
the climatological factors may balance their effect on 
the distribution of density. We shall not enter any fur- 
ther on this subject but shall, in the following, consider 
only the currents which are associated with the distri- 
bution of density. 

We shall first examine the currents in the tropo- 
sphere, which extend to a depth of about 500 meters. In 
the North Pacific the dominant feature is represented by 
the anticyclonic current system which has its center in 
latitudes 25° to 30° north, and in longitude about 180°. 
It is perhaps not correct, however, to use the term 
"center" because, apparently, we find an axis of maxi- 
mum elevation of the isobaric surfaces stretching from 
the region to the south of Japan toward the Hawaiian Is- 
lands. On the northern side of this axis we find currents 
toward the east, and on the southern side currents to- 
ward the west or southwest. 

A similar current system is probably present on the 
Southern Hemisphere, but our observations are not ex- 
tended over a sufficiently wide area to disclose the dif- 
ferent branches of this system. In our charts we find 
the westerly current represented between latitudes 0° 
and 20° south, although it appears to have a less stable 
character than the corresponding current in the North- 
ern Hemisphere. The easterly current is seen to the 
south of latitude 30° south between longitudes 80° and 
120° west. Between the tropical westerly currents we 
find the Equatorial Countercurrent which is in longitude 
140° north and latitude 11° north where it runs as a very 
strong and narrow current, and in longitude 175° west 
appears as a rather broad and weak current extending to 
both sides of the equator, but to the greatest distance on 
the northern side. 

It is of advantage to discuss separately the different 
branches of the current systems in the two hemispheres 
and we shall, as previously, begin with the most south- 
ern part of the South Pacific. 

In the southeastern part of the Pacific our charts 
show the northern branch of the South Pacific east drift. 
The current runs toward the east between latitudes 30° 
and 40° south, and can be followed from the surface to a 
depth of 500 meters, but the velocity decreases down- 
ward and is very small below 300 meters. Above a 
depth of 400 meters the current appears to turn toward 
the west in latitude 30° south, but below 400 meters a 
closed circulation appears to be present between longi- 
tudes 80° and 120° west. 



108 



OBSERVATIONS AND RESULTS IN PHYSICAL OCEANOGRAPHY 



The greater part of the water masses which are 
carried to the east does not turn toward the equator until 
reaching the South American coast, then it follows this 
coast toward the north as the Peruvian Current. This 
current can be traced to a depth below 500 meters. We 
have previously pointed out that water of low tempera- 
ture is found at a short distance from the surface off the 
coast of Peru, and that the surface temperatures are 
very low in this region. It cannot be doubted that these 
low surface temperatures are owing to a vertical move- 
ment which carries water of low temperature to the sur- 
face, but the accumulation of cold water off the coast can 
be explained without taking a possible vertical movement 
into consideration. We must bear in mind that water is 
transported toward the coast of South America by the 
predominating current toward the east. This water is 
forced to change its course and to continue toward the 
equator. The Peruvian Current is, thus, a "forced" 
current which must exist because of the land boundaries 
of the ocean. In such a current we must find the normal 
distribution of density, which means that in the Southern 
Hemisphere we must find water of high density on the 
right-hand side of the current and water of low density 
on the left-hand side. Consequently the density must in- 
crease toward the coast or, if the salinity is nearly con- 
stant, water of low temperature must accumulate along 
the coast. The accumulation of cold water along the 
coast of South American gives, therefore, no evidence of 
an upwelling motion which reaches to great depths, but 
indicates only that a current follows the coast toward the 
equator (cf. Helland-Hansen [1912]). On the other hand 
it is evident because of the conspicuously low surface 
temperatures, that water from moderate depths is drawn 
to the surface at the coast. This upwelling from moder- 
ate depths is probably maintained by prevailing winds 
and is a secondary effect as compared with the large ac- 
cumulation of cold water at greater depths. The actual 
surface current, which represents the combined effect of 
the distribution of density and of the wind, probably is 
directed away from the coast, for which reason the con- 
tinuity would necessitate a supply of water from below, 
that is, an upwelling. 

As to the direction of the winds which maintain the 
offshore currents, it should be borne in mind that on ac- 
count of the effect of the rotation of the earth, the trans- 
port of water by wind takes' place at right angles to the 
direction of the wind, to the right in the Northern Hemi- 
sphere and to the left in the Southern Hemisphere. The 
winds, therefore, which approximately parallel the coast 
toward the equator, give rise to a transport of water 
having an offshore component. 

It is well known that the regions of upwelling are all 
found at the west coasts of the continents where the wind 
currents transport water away from the land. The up- 
welling has, therefore, generally been attributed to the 
effect of the winds. The present interpretation of the ob- 
served conditions does not differ from the accepted ex- 
planation of the upwelling, but here it is emphasized that 
the upwelling water comes from small depths and that the 
the accumulation of cold water in greater depths is not a 
result of the upwelling but is associated with the pres- 
ence of a "forced" current along the coast. 

To the north of latitude 20° south we find, on the 
whole, currents which are directed toward the west. 
Here we have the region of the westerly tropical current 
in the South Pacific. This westerly current appears to 
be very irregular. In the region from the coast of Peru 



to longitude 120° west it appearsas if divergent currents 
are found to a depth of about 100 meters. These diverg- 
ing currents may be an effect of the prevailing east 
winds which carry the surface water to the north on the 
northern side of the equator and to the south on the 
southern side. If this is correct, we must assume that 
ascending motion takes place in the region to the south 
and the west of the Galapagos Islands, and such currents 
would account for the low surface temperature of this 
region. The high phosphate content of the surface water 
in this region supports such a conception. Below a 
depth of 200 meters water from the northwest appears to 
flow toward this region, perhaps compensating for the 
water which is drawn to the surface. Farther west, be- 
tween longitudes 120° and 170° west, we find that the 
currents have considerable components from the south 
down to a depth of about 200 meters. In this region, at 
a depth of between 100 and 200 meters, the southern part 
of Section V indicates a considerable northward flow of 
water of high salinity. The dynamic charts confirm that 
such a flow takes place above the 200-meter level be- 
cause the northerly component of the current is greatest 
down to this level. The irregularities in the topography 
of the isobaric surfaces perhaps indicate that the flow 
toward the equator of water of high salinity does not take 
place continuously but has an intermittent character. 
The fact that the irregularities are especially present 
above the 200-meter level points in this direction. An 
intermittent transport of water toward the equator means 
that whirls develop within which subsurface water may 
be transported to the surface. At several stations in this 
this region water of high phosphate content and low oxy- 
gen content is found, indicating that such transport takes 
place. 

Before concluding the discussion of the westerly 
tropical current, we shall emphasize that this current, 
aside from the wind current at the surface, dynamically 
is partly of the same character as the Peruvian Current. 
The water, which is transported toward the South Amer- 
ican coast by the easterly current in the South Pacific 
and is forced toward the equator along the continent, 
cannot sink because of its low density and must return 
toward the west as a surface current within which the 
easterly winds carry the light water to the south. The 
westerly tropical current is thus in part maintained by 
the same forces which maintain the easterly current in 
the southern part of the ocean and in part by the prevail- 
ing winds. In the Southern Hemisphere we find water of 
low density on the left-hand side of the current and water 
of high density on the right-hand side; that is, an accumu- 
lation of heavy water under the equator and an accumula- 
tion of light water to the south of the westerly current. 
This distribution of density must be regarded as a 
"forced" distribution owing to the limitation of the ocean 
in an east and west direction and to the effect of the pre- 
vailing winds. 

To the north of the equator a corresponding current 
is found, the westerly tropical current of the North Pa- 
cific. Observations are lacking for a great part of the 
North Pacific between the coast of Central America and 
longitude 130° west and our picture, therefore, is incom- 
plete. It appears, nevertheless, as if the form of the 
North American Continent is of considerable importance 
to the development of the currents. We shall deal fur- 
ther with this subject when discussing the California 
Current. 

The westerly tropical current in the North Pacific 



THE PACIFIC OCEAN 



109 



appear s to be stronger and more regularly developed than 
the corresponding current in the Southern Hemisphere. 
The former current must also be regarded as a forced 
current which is maintained partly by the prevailing 
winds and partly by the factors driving the easterly cur- 
rent of the northern part of the ocean, namely, the dif- 
ferences in density between the subtropical and the sub- 
arctic water. Since the North Pacific is limited on the 
north, the entire mass of water which is carried toward 
the east in the North Pacific must return, whereas in 
the South Pacific a considerable part of the water con- 
tinues eastward to the south of South America. This 
circumstance perhaps explains the more conspicuous 
development of the westerly tropical current in the 
North Pacific. 

Off the coast of Japan, in the latitude of Yokohama 
and to the north of this latitude, we find very complicated 
currents. No lines have been drawn, but by means of the 
numerical values on the chart, one easily recognizes the 
line of demarcation, representing the boundary between 
the warm water to the south and the cold water to the 
north, which was seen in Section IX. A warm current, 
theKuroshio, can be traced as a narrow and very strong 
current which follows the southeast coast of Japan to ap- 
proximately latitude 37° ?iorth. Here it meets the cold 
current coming from the northeast, the Kurile (Oyashio) 
Current. Both currents bend toward the east, the Kuro- 
shio partly to the south and the Kurile Current partly to 
the north. Along the border of the two currents a suc- 
cession of whirls is apparently developed and it is prob- 
able that future observations will show that these whirls 
develop at various places along the line of demarcation 
and reach varying intensities. The observations of the 
Carnegie indicate the major features of the current sys- 
tem but cannot be used for a discussion of the details. 
We remind the reader that a corresponding region with 
great contrasts is found in the North Atlantic to the south 
of the Grand Banks, and that corresponding whirls un- 
doubtedly are developed there. 

The whole of the North Pacific to the north of lati- 
tude 30° north is dominated by the easterly current, 
which in the southern part carries warm water of high 
salinity, and in the northern part carries cold water of 
low salinity. Because of the difference in temperature, 
the density is increasing toward the north. The observa- 
tions of the Carnegie cannot disclose any details as to 
this current, but they show that it is strongly developed 
to a depth of more than 500 meters. The inclination of 
the isobaric surfaces toward the north in the North Pa- 
cific is the dominating feature in the topography of the 
surfaces. 

The easterly current of the North Pacific divides 
into two branches when it strikes the coast of North 
America. The northern branch turns toward the north 
and bends into the Gulf of Alaska and returns toward the 
west on the southern side of the Aleutian Islands. This 
branch is shown in the British Admiralty Charts and in 
the chart by Merz, and appears in our charts, thanks to 
the observations made in the Gulf of Alaska by the United 
States Bureau of Fisheries. 

The other and more important branch of the easterly 
current of the North Pacific bends toward the south. The 
form of the North American coast is probably of great 
importance to the turning of the current, and to the fact 
that the southerly current along the coast runs with a 
very high velocity off the coast of California where it is 



known as the California Current. As in the case of the 
Peruvian Current, the increase of density toward the 
coast cannot be ascribed to an upwelling of deep water, 
but is dynamically conditioned. The California Current, 
as it appears on our dynamic maps, is maintained by the 
difference of density between the subtropical and sub- 
arctic regions, but the increase in density toward the 
coast is a direct result of the existence of the current. 

An upwelling takes place in the upper layers because 
of the transport of water away from the shore by pre- 
vailing winds. Thorade (1909) has shown that this trans- 
port and, consequently, the upwelling is subjected to 
considerable seasonal change. As to the character of 
the upwelling and the relation of this phenomenon to the 
low temperatures at greater depths, we refer to our 
discussion of the Peruvian Current. In this place it 
should again be emphasized that according to our con- 
ception the low surface temperatures are the result of 
an upwelling of water from small depths, whereas the 
low temperatures at greater depths have nothing to do 
with the upwelling, but are associated with the presence 
of a southerly current along the coast. 

The rapid heating of the surface, which takes place 
in this southerly latitude, must lead to the development 
of a thin surface layer of relatively high temperature. 
The transition from this surface layer to the underlying 
water takes place in a short distance, and convective 
currents therefore cannot penetrate to any great depth. 
The velocity of the California Current decreases with 
increasing depth and at a depth of 400 meters the cur- 
rent is very weak. 

In the regions between the coast of California and the 
Hawaiian Islands the currents are rather irregular. At 
the most northern stations we find, on the whole, an east- 
erly current and at the most southern stations a wester- 
ly current, and between the Islands and the American 
coast the water flows mainly from the north. From the 
appearance of sections VII and XV, and from the curves 
showing the vertical distribution of temperature and sa- 
linity at stations 139 to 146, it appears as if a transport 
of water toward the north takes place in the upper layers 
at stations 142 to 146. The dynamic charts do not indi- 
cate such a transport, which perhaps must be attributed 
to the effect of the wind. Below a level of 200 or 300 
meters the transport appears to take place principally 
from the west. 

At the stations in the immediate vicinity of the Ha- 
waiian Islands we find a rather strong surface current 
from the east which, however, decreases rapidly in ve- 
locity with increasing depth. The water of high salinity, 
which is found below the surface at stations 139 and 140, 
appears to come from the region of high salinity to the 
west. 

The Equatorial Countercurrent is especially well de- 
developed in the Pacific. As a rule it is a little to the 
north of the equator, running with high velocity toward 
the east. It is probable that this current is extended 
across the whole width of the Pacific Ocean but it is un- 
doubtedly subjected to considerable variations, partly of 
seasonal character and partly owing to circumstances of 
which we have no knowledge. It is generally assumed 
(Defant, 1928; Krtimmel, 1911) that the Equatorial 
Countercurrent represents a compensation current car- 
rying back again to the east part of the water which is 
transported toward the west by the trade-wind currents. 
Furthermore, it is assumed that this countercurrent, 



110 



OBSERVATIONS AND RESULTS IN PHYSICAL OCEANOGRAPHY 



which is known to be a narrow current on the surface, 
widens with depth. The latter conception, as to the in- 
creasing width of the Equatorial Countercurrent, cannot 
be upheld according to the Carnegie results; on the con- 
trary, the current is typical of the upper layers only, 
and since it has a very limited extension it must be 
doubted that this flow of water represents a compensa- 
tion action. It will be shown on the basis of the Carne - 
gie data that the countercurrent probably is owing to the 
asymmetric development of the westerly tropical cur- 
rents of the two hemispheres and to the effect of diverg- 
ing surface currents in the vicinity of the equator. 

Before turning to the observations of the Carnegie 
a few general considerations are necessary. Attention 
should be drawn to the fact that the inclination of the 
isobaric surfaces must change when passing the equator 
because of the change of the direction of the deflecting 
force of the earth's rotation. In other words, the iso- 
baric surfaces must have a maximum or a minimum at 
the equator. If the isobaric surfaces had a definite in- 
clination at the equator, the direction of the current 
would change by 180° when passing the equator and such 
a condition cannot be stable. 

If the isobaric surfaces show a maximum at the 
equator, the surfaces are inclined to the north in the 
Northern Hemisphere and to the south in the Southern 
Hemisphere, and the current is directed toward the east 
on both sides. If, on the other hand, the isobaric sur- 
faces have a minimum at the equator the current is di- 
rected toward the west. 

We have seen previously that the westerly tropical 
currents in both hemispheres must be regarded as 
forced currents, which are maintained partly by the pre- 
vailing winds and partly by the density currents in the 
northern and southern parts of the ocean. Within these 
westerly tropical currents in the Northern Hemisphere 
we must have the heavy water to the left, which means 
near the equator, and in the Southern Hemisphere the 
heavy water must lie to the right, which also means near 
the equator. Therefore, since these forced currents to- 
ward the west exist, we must find an accumulation of 
heavy water in the vicinity of the equator. Assuming, for 
for the sake of simplicity, that we have two layers only, 
one light on top and one heavy below, the conditions have 
been represented schematically in figure 24a, in which 
the boundary surface between the two water masses 
shows an upheaval under the equator. Assuming the iso- 
baric surfaces in the heavy water to be horizontal, the 
isobaric surfaces must have the courses which are in- 
dicated by means of the thin lines. In this case the to- 
pography of the isobaric surfaces shows a minimum at 
the equator, and within the light water, we find a current 
toward the west on both sides of the equator, whereas 
the heavy water is at rest. No countercurrent exists. 

If, however, for some reason the accumulation of 
heavy water is asymmetric when referred to the equator, 
a different system is developed. The conditions which 
are shown in figure 24b cannot exist. We cannot find a 
single upheaval of the heavy water on one side of the 
equator because this would give the isobaric surfaces an 
inclination at the equator. Considering that the isobaric 
surfaces must have a maximum or a minimum at the 
equator, two types of asymmetric development are pos- 
sible, as shown in figures 24c and 24d. In figure 24c we 
have a small upheaval of the heavy water under the equa- 
tor and a big upheaval to the north. When such a distri- 
bution of density is present, the isobaric surfaces show 



two minima, one at the equator and one to the north of 
the equator. These two minima are separated by a 
maximum and the water in the region between this max- 
imum and the northern deep minimum must flow to the 
east. That means that here we find a countercurrent 
which, however, is present in the upper light water only. 
The light water reaches to greater depths to the north 
and to the south of the minima and the westerly current 
is, therefore, deeper than the countercurrent. In the 
second case, figure 24d, we find accumulations of heavy 
water on both sides of the equator but the accumulation 
on the northern side is the greater. The isobaric sur- 
faces show a maximum at the equator and minima on 
both sides, and between the two minima a countercurrent 
flows toward the east. The case in which the two up- 
heavals of the heavy water are equally developed is 
probably of minor interest because then symmetry 
exists as to the equator and the simpler system in fig- 
gure 24a seems more probable. The greatest upheaval 
may, of course, be found in the Southern Hemisphere, 
but this cannot lead to any principal differences. 

From these considerations it seems probable that an 
asymmetric development of the westerly tropical cur- 
rents may give rise to an asymmetric accumulation of 
heavy water near the equator, and that the dynamic sys- 
tem which then is established leads to the countercur- 
rent toward the east between the two westerly currents. 
The width of the countercurrent and the one-sided devel- 
opment in reference to the equator depends on the char- 
acter of the asymmetry, but the countercurrent must in 
all cases be regarded as a dynamically conditioned cur- 



rent 



1 



We have the possibility of discussing the equatorial 
currents for two occasions when the Carnegie crossed 
the equator. The sections were both taken in directions 
which form angles less than 90° with the equator, but, 
for the sake of simplicity, we shall plot the values as if 
they were taken along two meridians; that is, we shall 
plot the stations at the observed latitudes and disregard 
the differences in longitude between the stations. The 
eastern section is taken nearly in the central part of the 
Pacific along the average meridian of 145° west, where- 
as the western section is taken in the western half of the 
Pacific approximately along the meridian of 180°. 

In order to study these sections we have computed 
the distances in dynamic meters between the isobaric 
surface of 700 decibars and the isobaric surfaces 0, 50, 
100, 150, 200, 250, and 300 decibars. We have selected 
the isobaric surface of 700 decibars as the reference 
surface because this surface is practically parallel to 
the surface of 2000 meters. Also, accidental errors of 
observation exercise a greater influence at depths be- 
low 700 meters since the intervals between the observa- 
tions there are greater. Assuming the isobaric surface 
of 700 decibars to be horizontal, we have constructed 



1 Later on the author (1939) has pointed out that the 
observed distribution of mass does not given any clue to 
the understanding of the dynamics of the countercurrent. 
The dynamics have recently been discussed by Mont- 
gomery (1940) and by Montgomery and Palmen (1940). 
They state that the trade winds by continually exerting a 
westward stress on the sea surface produce a westward 
ascent of the sea level in the equatorial region. The 
equatorial countercurrents are found in the doldrums 
and apparently result as a down slope flowing in this 
zone where the winds maintaining the slope are absent. 



THE PACIFIC OCEAN 



111 



profiles of the isobaric surfaces down to the surface of 
300 decibars. Furthermore, we have represented the 
distribution of density, salinity, and temperature by 
means of vertical sections which are extended to a depth 
of 300 meters, and in the case of the central section we 
have also represented the amount of oxygen, but from 
the western section no observations of oxygen are avail- 
able. 

The profiles of the isobaric surfaces of the central 
section are represented in figure 25. As in the other 
vertical sections, north is to the right and south is to the 
left. These profiles are of the type shown schematically 
in figure 24c. When drawing them, one has a certain 
freedom because of the considerable distances between 
the stations, but a minimum must be placed somewhere 
near the equator, and then it is permissible to place it at 
the equator where it theoretically should be. 

It is seen on the figures that currents toward the 
west are dominating. At the surface they are found to 
the north of latitude 10° north and to the south of latitude 
03° 40' north. Currents in the opposite direction, to- 
ward the east, are at the surface between the two lati- 
tudes 10° and 7° 30' north. Within these latitudes the 
Equatorial Countercurrent is fully developed. The most 
interesting feature shown by the profiles is that the ve- 
locity of the countercurrent decreases very rapidly with 
increasing depth. At a level of 100 meters it is already 
much weaker than at the surface, and at a level of 200 
meters it has practically disappeared. The westerly 
current also decreases with increasing depth, especially 
near the equator, but in latitudes 20° north and 10° south 
a considerable current toward the west still exists at 
300 meters. These observations show that the Equatori- 
al Countercurrent does not widen with depth but, on the 
contrary, becomes narrower and narrower, and disap- 
pears above a level of 200 meters. 

Turning next to the western section, figure 30, we 
find essentially the same features but here the profiles 
of the isobaric surfaces are of the type shown in figure 
24d. In this case, a maximum must be placed some- 
where near the equator, and it is permissible to place it 
at the equator, in agreement with the theoretical condi- 
tions. 

The currents toward the west are also dominating 
here, extending to the north of latitude 6° 20' north and 
to the south of latitude 3° 20' south. Between latitudes 
6° 20' north and 3° 20' south the current runs in the 
opposite direction, toward the east. In this case we find 
a maximum elevation of the isobaric surfaces at the 
equator. The Equatorial Countercurrent is thus extend- 
ed over a broad area on both sides of the equator. It 
has its maximum velocity somewhat below the surface 
at a level of about 100 meters but from this level the 
velocity decreases rapidly with increasing depth until 
the current practically disappears at 300 meters. The 
currents toward the west also decrease with increasing 
depth, especially at the shortest distance from the equa- 
tor as was the case in the preceding section. The two 
sections give us essentially the same results. The dif- 
ferent position and development of the countercurrent 
may perhaps be explained by the fact that the western 
section was taken in April, at the beginning of the north- 
ern summer, whereas the central section was taken in 
November, at the beginning of the southern summer, 
but it also may be related to the different geographic lo- 
cations. 

The different development of the countercurrent at 



the two crossings of the equator makes it impossible to 
combine the observations to form a consistent picture of 
the topography of the isobaric surfaces in the vicinity of 
the equator. There the lines of equal elevation in the 
charts, therefore, have no physical significance. 

The density sections, figures 26 and 31, give the 
same picture in both cases. We find accumulations of 
heavy water under the northern and southern borders of 
the countercurrent, whereas lighter water extends to 
greater depths within the countercurrent itself. In the 
central section the upheaval of the cold water is espe- 
cially characteristic at the northern border of the 
countercurrent. 

Turning to the salinity, temperature, and oxygen 
sections, figures 27, 28, and 29 from the central region, 
we obtain some information as to the character of the 
vertical motion. From the salinity sections it is evident 
that we find ascending motion along the borders of the 
westerly currents. The ascending motion is especially 
strong on the northern side of the countercurrent, where 
water of low salinity is brought practically to the sur- 
face. The course of the isohalines indicates that the 
surface water is driven away from the countercurrent 
both on the northern and the southern sides, and the sa- 
linity section, therefore, supports the opinion that di- 
verging surface currents are present and are of impor- 
tance to the development of the system. The tempera- 
ture section discloses the same features as the salinity 
sections. It shows especially the upward movement on 
both sides of the countercurrent and, in addition, a 
downward movement at the southern boundary.. 

The oxygen section, figure 29, shows some very in- 
teresting features. The axis of the lowest salinity 
values in the salinity section follows exactly the line of 
4 ml/L. The ascending water on the northern side has 
thus, on the whole, an oxygen content above 4 ml/L. On 
the southern side we find that the ascending water has a 
somewhat lower oxygen content, namely, 3 ml/L. The 
descending movement at the southern boundary of the 
countercurrent can hardly reach to any considerable 
depth because even in the central part we find a rapid 
decrease of the oxygen content below a level of 150 me- 
ters. 

A very rapid change of density with depth is found at 
a short distance below the surface at the stations where 
the heavy deep water reaches almost to the surface, and 
where the stable stratification prevents mixing between 
surface water and the deep water. The deep water, 
which rises as a wedge at the northern border of the 
countercurrent, is without any communication with the 
surface water and consequently we find that this deep 
water is practically without oxygen. Values as low as 
0.03 ml/L were observed in this region and values below 
0.25 ml/L occur within an extensive mass of water. The 
contrasts are smaller on the southern side of the counter- 
current where the density changes more gradually with 
depth, and where a slow mixing between the surface 
waters and the deep waters may take place. 

The western temperature and salinity sections show 
several features which are similar to those of the cen- 
tral regions, but the contrasts are less conspicuous and 
the indications of vertical movement are less definite. 
From the salinity section it is evident that ascending 
motion takes place along the borders of the westerly 
currents, especially on the northern side of the counter- 
current. 

The conditions which are revealed by the observations 



112 



OBSERVATIONS AND RESULTS IN PHYSICAL OCEANOGRAPHY 



of the Carnegie are in close agreement with our general 
considerations. On both sides of the equator we find 
westerly currents reaching to considerable depths and 
there separated by heavy water which is practically at 
rest. Between the westerly currents the countercurrent 
is embedded as a swift but shallow current. The heavy 
water at rest reaches nearest the surface at the northern 
and southern boundaries of the countercurrent. 

Intermediate Currents 

We have already discussed the origin of the interme- 
diate water of low salinity in the Southern Hemisphere 
and have shown that this water probably sinks at the Ant- 
arctic convergence. When studying the sections we 
found the axis of the intermediate current at a depth of 
600 to 700 meters within the areas from which observa- 
tions are available. These areas are so limited, how- 
ever, that we cannot follow the flow of the iivisr mediate 
current and our dynamic charts give only some hints as 
to the character of this current. From the dynamic 
charts for the levels 500, 700, and 1000 meters it looks 
as if the circulation of the intermediate current takes 
place in a clockwise direction, contrary to the tropo- 
spheric circulation which is counterclockwise. This 
result needs confirmation, but what seems certain is 
that the flow of the water takes place principally in an 
east and west direction and that the north and south com- 
ponent of the current is very weak in the central part of 
the South Pacific. The flow of water, which at the 700- 
meter level is directed away from the coast of South 
America, perhaps transports back again part of the water 
which is carried toward the coast by the currents of the 
troposphere. The westerly current off the coast at a 
depth of 700 meters should then be regarded as a com- 
pensation current. 

In the Northern Hemisphere the circulation of the 
intermediate water takes place in the same direction as 
the circulation within the troposphere and is in both 
cases clockwise. We have seen that the intermediate 
water probably is formed in the eddies which develop off 
the coast of Japan at the boundary between the warm cur- 
rent from the southwest and the cold current from the 
northeast. Water of a salinity between 33.09 and 34.00 
per mille and of a temperature of about 5°, which is 
formed in this region, is transported toward the east, 
turns toward the south when approaching the American 
coast, and returns toward the west in approximately 
latitude 20° north. On this journey both the temperature 
and the salinity of the water increase because of the 
processes of mixing. The water, therefore, has a higher 
temperature and a higher salinity when it bends toward 
the north on the west side of the ocean after having com- 
pleted one circuit, than it had when beginning the circuit. 
When carried toward the north it is mixed with water of 
lower temperature and lower salinity coming from the 
north, and new water of the typical properties of the 
intermediate layer is again formed. This new water 
compensates for the loss which has taken place because 
of the processes of mixing, and because a transport of 
intermediate water toward the equator probably exists, 
as was shown when dealing with the Equatorial Counter- 
current. 

The intermediate current in the Northern Hemi- 
sphere is, on the whole, a subsurface current, in con- 
trast with the corresponding current in the Southern 
Hemisphere which originates at the surface. The differ- 



ence in the oxygen content of the intermediate water sup- 
ports this conception (see p. 50). 

Velocity of Currents between the Surface and 700 Meters 

Up to this point the discussion of the currents has 
been based on the topography of the isobaric surfaces, 
and the currents have been treated qualitatively only. 
Current charts to 700 meters (figs. 34 to 38) show di- 
rection and velocity of the currents, as computed from 
the inclination of the isobaric surfaces, supposing that 
the conditions are stationary, and that the motion is 
frictionless and negligible at the 2000-decibar surface. 
It must again be emphasized that the values in the fig- 
ures are obtained by combining observations, which in 
several regions were made at great intervals of time. 
This combination may lead to apparent irregularities, 
especially in regions where the currents undergo consid- 
erable displacement. Also in the vicinity of the equator 
the computed velocities are uncertain because of the to- 
pography of the isobaric surfaces and because there the 
friction may play a greater part than elsewhere. In spite 
of these reservations, however, it is probable that the 
charts show the approximate order of magnitude of the 
currents which are maintained by the distribution of 
density. 

In the Southern Hemisphere the easterly current of 
the South Pacific shows velocities which, at the surface, 
vary from 2 to 9 cm/sec, increase to a depth of 100 me- 
ters where they reach 12 cm/sec, and decrease rapidly 
below 100 meters. At 400 meters the eastward velocities 
are only 3 cm/sec or less, and at 700 meters the direc- 
tion is reversed, the water flowing toward the west with 
a velocity of 1 to 2 cm/sec. The Peruvian Current ap- 
pears to be a very weak current. At the surface the ve- 
locities range from 2 to 5 cm/sec and decrease down- 
ward to about 2 cm/sec at 700 meters. 

Within the westerly tropical current of the South Pa- 
cific we find surface velocities up to 30 cm/sec, 14 nau- 
tical miles in 24 hours. Still greater velocities are met 
with at 100 meters, but below this level the velocities 
decrease rapidly and at 700 meters no distinct motion 
toward the west is perceptible. The irregular character 
of the westerly tropical current of the Southern Hemi- 
sphere is clearly evident from the figures. 

In the northern Hemisphere the westerly tropical 
current shows the greatest velocities near the surface, 
where they approach 30 cm/sec. The velocities de- 
crease with increasing depth, and at the same time the 
current is being displaced toward the north. At 700 
meters the velocities are less than 2 cm/sec. 

At the surface, in longitude 140° west, the Equatori- 
al Countercurrent has a velocity of about 50 cm/sec, or 
nearly 24 nautical miles in 24 hours. This value is 
again very probable. At greater depths the countercur- 
rent disappears, and the crosscurrents, which are shown 
at 700 meters, probably have no real significance. 

The warm current along the coast of Japan, the Kuro- 
shio, is not represented in the figures, but the cold 
Kurile Current (Oyashio) is seen at all levels. The ve- 
locity of this current decreases from 17 cm/sec at the 
surface to about 2 cm/sec at 700 meters. The changes 
in the direction of the current with depth are perhaps 
associated with the presence of whirls. 

The easterly current in the northern part of the 
North Pacific can be traced at all levels. The velocities 
decrease with increasing depth, from 2 to 9 cm/sec at 



THE PACIFIC OCEAN 



113 



the surface and 100 meters to 0.8 - 3 cm/sec at 700 me- 
ters. 

The westerly current in the Gulf of Alaska has a ve- 
locity of 7 cm/sec at the surface, but at 400 meters it 
has practically disappeared. The southerly current along 
the coast of California shows a velocity of 17 cm/sec at 
the surface. This velocity also decreases downward, but 
below 400 meters the decrease appears to be very small 
because at the levels 400 and 700 meters the computed 
velocities are 4.3 and 4.2 cm/sec respectively. 

The numerical values which are shown in the figures 
and briefly treated here give, no doubt, a fairly correct 
idea of the intensity of the circulation in the Pacific, 
especially in the North Pacific, down to a depth of 700 
meters, but the picture will probably be much modified 
in details when more observations become available. 

Flow of the Deep Water 

Since high temperatures are found in the equatorial 
regions, it is probable that a slow descending motion 
takes place here and that the circulation is to some ex- 
tent, therefore, as suggested by Wtist (1930). The de- 
scending water, however, cannot contribute directly to 
the formation of the typical deep water because of its 
high temperature and low salinity, but must spread to the 
north and the south above the deep water. 

In the North Pacific the bottom water and the deep 
water must come from the south because it cannot be 
formed anywhere in the area of the North Pacific. The 
inflow probably takes place near the bottom because 
there the highest oxygen values are found. The low tem- 
peratures in the northern part of the North Pacific at the 
levels below 2000 meters suggest an ascending motion of 
the deep water in this region. If this is correct, we must 
assume that the deep water returns to the south at a 



level between 2000 and 1000 meters, and on this journey 
it is being mixed with water from the intermediate cur- 
rent. 

The deep water of the South Pacific must also come 
from the south and the greater part probably enters the 
Pacific to the south of New Zealand. Part of the deep 
water flowing into the South Pacific continues to the 
North Pacific, but another part probably ascends when 
approaching the equator and returns to the south at 
levels above 2000 meters. The distribution of oxygen 
leads to this suggestion. 

It has already been indicated that at levels above 
2000 to 1000 meters the water of the North Pacific prob- 
ably moves to the south and thus flows into the South 
Pacific. At levels below 1000 meters the oxygen con- 
tent, however, is much higher in the South Pacific than 
in the North Pacific, and this could not be the case if 
the water at these levels came from the North Pacific 
only. Therefore, in the South Pacific the return current 
above 2000 meters must carry water which mainly has 
been circulating in the South Pacific only, and with 
which some water from the North Pacific has been 
mixed. 

It must be emphasized, however, that at any level the 
flow in an east-west direction is considerably stronger 
than the flow in a north-south direction. Because of 
this circumstance and of the obvious differences in the 
currents of the eastern and western parts of the ocean, 
no attempt has been made to give a schematic represen- 
tation of the meridianal circulation in the Pacific Ocean. 
Such a representation would contain too many hypotheti- 
cal elements, because at present it is not possible to 
arrive at any definite conclusions as to the flow of the 
deep water. Some possibilities have been suggested but 
these and others cannot be examined more closely be- 
fore a greater number of observations are at hand. 



LITERATURE CITED 



Clowes, A. J. 1833. Influence of the Pacific on the cir- 
culation in the South-West Atlantic Ocean. Nature, 
vol. 131, London. 

Defant, A. 1928. Die systematische Erforschung des 
Weltmeeres. Ztschr. Gesellsch. Erdk., Sonderband 
zur Hundertjahrfeier. Berlin. 

Discovery Reports. 1930. Vol. 3. Cambridge. 

Helland-Hansen, B. 1912. The depths of the ocean by 
Sir John Murray and Dr. Johan Hjort. Physical 
Oceanography, p. 276. London. 

1918. Nogen hydrografiske metoder. Skand. 

Naturforsker mote, Kristiania (Oslo). 

1930. Physical oceanography and meteorology. 

Rept. Sci. Results Michael Sars N.Atlantic deep-sea 
exped., 1910. Bergen. 

and F. Nansen. 1926. The Eastern North At- 
lantic. Geof. Pub., vol. 55, no. 2. Oslo. 

Howard, A. 1940. Hydrology, Programme of work and 
record of observations. B.A.N.Z. Antarctic Res. 
Exped. 1921-1931. Repts. ser. A, vol. 3, Oceanog- 
raphy, pt. 2, sec. 2, pp. 24-86. 

Jacobsen, J. P. 1929. Contribution to the hydrography 
of the North Atlantic. The Danish Dana exped., 1920- 
1922, no. 3. Copenhagen. 

Krummel, Otto. 1911. Handbuch der Ozeanographie, 
vol. 2. 

Moller, L. 1929. Die Zirkulation des Indischen Ozeans. 
Auf Grund von Temperatur-und Salzgehaltstiefen- 
messunger und Oberflachenstrombeob^chtungen. 
Inst. f. Meeresk., VerOff., N.F., A, no. 21, 48 pp. 

Montgomery, R. B. 1940. The present evidence of the 
importance of lateral mixing processes in the ocean. 
Bull. Amer. Meteorl. Soc, vol. 21, pp. 87-94. 

and E. Palmen. 1940. Contribution to the 

question of the Equatorial Counter cur rent. Jour. 
Marine Res., vol. 3, pp. 112-133. 

Mosby, Haakon. 1934. The waters of the Atlantic Ant- 
arctic Ocean. Sci. Results Norwegian Antarctic 
Exped. 1927-1928 et sqq., instituted and financed by 
Consul Lars Christensen. No. 11. Det Norske 
Videnskapsakademi, Oslo. 



Palmen, E. 1930. Ein Beitrag zur Berechnung der 
Stromungen in einem begrenzten und geschichten 
Meere. Rap. et Proces-Verbaux des Reunions du 
Conseil Perm. Internat. Expl. Mer, vol. 64. Copen- 
hagen. 

Puis, C. 1895. Oberflachentemperaturen usw. des 
Aquatorialgurtels des Stillen Ozeans. ArchivDeut. 
Seewarte, vol. 18, no. 1. 

Schott, G. 1928. Die Verteilung des Salzgehaltes im 
Oberflachenwasser der Ozeane. Ann. d. Hydrogr., 
vol. 56, pp. 145-166. Berlin. 

and F. Schu. 1910. Die Warmeverteilung in den 

Tiefen des Stillen Ozeans. Ann.d. Hydrogr., vol. 38. 
Berlin. 

Sverdrup, H. U. 1931. The origin of the deep water of 
the Pacific Ocean. Ger lands Beitr. zur.Geophysik, 
vol. 29. Leipzig. 

1939. Oceanic circulation. Proc. Fifth Internat. 

Cong. Applied Mech., 1938, pp. 279-293. New York. 

1940. Hydrology, Discussion. B.A.N.Z. Ant- 
arctic Res. Exped. 1921-1931. Repts. ser. A, vol. 3, 
Oceanography, pt. 2, sec. 2, pp. 88-126. 

Thorade, H. 1909. Ueber die Kalifornische Meeress- 

trOmung. Ann. d. Hydrogr., vol. 37, pp. 17-34, 63- 

76. 
Wust, G. 1928. Der Ur sprung des Atlantischen Tiefen- 

wasser. Ztschr. Gesellsch. Erdk. Sonderband zur 

Hundertjahrfeier. Berlin. 

1929. Schichtung und Tiefer zirkulation des 

Pazifischen Ozeans. VerOff. Ins:. Meeresk., N.F., 
A, no. 20. Berlin. 

1930. Meridionale Schichtung und Tiefenzirku- 

lation in den Westhalften der drei Ozeane. Jour, du 
Conseil Internat. Expl. Mer, vol. 5, no. 1. Copen- 
hagen. 

1935. Schichtung und Zirkulation des Atlanti- 
schen Ozeans. Die Stratosphare. Wissensch. Erbegn. 
d. Deut. Atlantischen Exped. auf dem Forschungs-und 
Vermessungsschiff Meteor 1925-1927, vol. 6, pt. 1, 
sec. 2. Berlin. 



114 



FIGURES 1-38 

TITLE 

Page 
Fig. 1- -Salinity-temperature relation, Central North Atlantic Ocean, Stations 3, 5, 6, 15, 

16, Carnegie results, 1928 117 

Fig. 2--Temperature-salinity relation, Atlantic Ocean, from Michael Sars, Armauer 

Hansen, and Carnegie results 118 

Fig. 3--Composite temperature -salinity relation, Stations 20-34, Atlantic Ocean and 

Caribbean Sea, from Carnegie results, 1928 • 119 

Fig. 4--Composite temperature -salinity relation, deep water Atlantic Ocean, from 

Carnegie results, 1928 120 

Fig. 5--Dynamic topography of the 100-decibar surface relative to the 2000-decibar 

surface, North Atlantic Ocean 120 

Fig. 6- -Profile isobaric surfaces, Atlantic Ocean, from Carnegie results, 1928 121 

Fig. 7 --Stations of temperature and salinity observations, depths greater than 3000 

meters, Pacific Ocean, Carnegie and previous values 122 

Fig. 8--Vertical distribution temperature in central part of Pacific 123 

Fig. 9--Vertical distribution salinity in central part of Pacific 123 

Fig. 10- -Vertical distribution temperature in western part of Pacific (according to Wiist) 123 

Fig. 11- -Vertical distribution salinity in western part of Pacific (according to Wiist) 123 

Fig.l2--Comparison temperature observations, Challenger, 1875, and Carnegie, 1929 124 

Fig,13--Composite temperature- salinity relation, regions 1-2, Pacific Ocean, from 

Carnegie results, 1928-1929 125 

Fig.l4--Composite temperature-salinity relation, regions 3-4, Pacific Ocean, from 

Carnegie results, 1928-1929 126-127 

Fig. 15 --Composite temperature -salinity relation, regions 5-6, Pacific Ocean, from 

Carnegie results. 1928-1929 128-129 

Fig.l6--Composite temperature-salinity relation, regions 7-9, Pacific Ocean, from 

Carnegie results, 1929 130-131 

Fig.l7--Composite temperature-salinity relation, regions 10-11, Pacific Ocean, from 

Carnegie results. 1929 132 

Fig. 18- -Composite temperature-salinity relation, regions 12-14, Pacific Ocean, from 

Carnegie results, 1929 133 

Fig. 19- -Regions where temperature- salinity relation is nearly the same in each region, 

Pacific Ocean, from Carnegie results, 1928-1929 134 

Fig. 20A- -Composite temperature-salinity relation, Pacific Ocean, from Carnegie 

results, 1928-1929 135 

Fig. 20B- -Surface temperatures and salinities corresponding to characteristic values of 

intermediate water in both hemispheres 136 

Fig.21--Bottom temperatures of water for bottom depths greater than 3000 meters, 

Pacific Ocean, from Carnegie results, 1929 137 

115 



116 OBSERVATIONS AND RESULTS IN PHYSICAL OCEANOGRAPHY 



Page 



Fig.22--Current-chart, Pacific Ocean, from observations of salinity and temperature 

of sea water by the Carnegie. 1928-1929 138 

Fig.23--Pacific currents in northern summer from preliminary sketch by A.Mertz 138 

Fig. 24- -Schematic representation possible fields density and pressure, vicinity of 

equator, from Carnegie results. 1928-1929 139 

Fig. 25- -Profile isobaric surfaces, from Carnegie results, 1929 139 

Fig.26- -Vertical distribution density, north-south section crossing equator, from 

Carnegie results, 1929 140 

Fig. 27- -Vertical distribution salinity, north-south section crossing equator, from 

Carnegie results, 1929 140 

Fig.28- -Vertical distribution temperature, north-south section crossing equator, from 

Carnegie results, 1929 141 

Fig.29--Vertical distribution oxygen, north-south section crossing equator, from 

Carnegie results. 1929 141 

Fig.30- -Profile isobaric surfaces, from Carnegie results. 1929 142 

Fig.31- -Vertical distribution density, north-south section crossing equator, from 

Carnegie results. 1929 142 

Fig. 32- -Vertical distribution salinity, north-south section crossing equator, from 

Carnegie results. 1929 143 

Fig.33--Vertical distribution temperature, north-south section crossing equator, from 

Carnegie results, 1929 143 

Fig.34- -Current-chart, Pacific Ocean, at surface relative to assumed zero current 

at 2000 meters, from Carnegie results, 1928-1929 144 

Fig.35--Current-chart, Pacific Ocean, at 100 meters relative to assumed zero current 

at 2000 meters, from Carnegie results, 1928-1929 145 

Fig. 36- -Current-chart, Pacific Ocean, at 200 meters relative to assumed zero current 

at 2000 meters, from Carnegie results, 1928-1929 146 

Fig. 37- -Current-chart, Pacific Ocean, at 400 meters relative to assumed zero current 

at 2000 meters, from Carnegie results, 1928-1929 147 

Fig.38--Current-chart, Pacific Ocean, at 700 meters relative to assumed zero current 

at 2000 meters, from Carnegie results, 1928-1929 148 



-20 



35.0 



i 1 r 



"355 ' ' ' ' 36.0 

SALINITY (PER MILLE) 




Sta 



t 



POSITIONS OF STATIONS 



STA- 


LAT 


LONG. 


TION 


NORTH 


WEST 


3 


44 00 


36 10 


5 


43 15 


31 32 


6 


50 22 


13 31 


15 


38 39 


48 48 


16 


36 47 


46 31 




-J I I l_ 



FIG. I —SALINITY-TEMPERATURE RELATION, CENTRAL NORTH ATLANTIC OCEAN, 
STATIONS 3, 5, 6, 15, 16, CARNEGIE RESULTS, 1928 



117 























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SYMBOLS 

1- 12 


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STATIONS 
DEPTH 
meters 

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8 

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TEMPERATURE 

(DEGREES CENTIGRADE) 






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>3000 o 





FIG. 4 — COMPOSITE TEMPERATURE-SALINITY RELATION, DEEP WATER ATLANTIC OCEAN, FROM CARNEGIE RESULTS, 1928 




FIG. 5 — DYNAMIC TOPOGRAPHY OF THE 100-DECIBAR SURFACE RELATIVE TO THE 2000-DECIBAR SURFACE, NORTH 

ATLANTIC OCEAN 



120 



24 23 22 21 20 



16 15 14 




HORIZONTAL SCALE 1 ■ ■ ■ 4 ?° ■ 8 ? 0KM SECTION I 

FIG. 6 — PROFILE ISOBARIC SURFACES, ATLANTIC OCEAN, FROM CARNEGIE RESULTS, 1928 



121 




122 



ffi 2000 




S 60° 40 20 20° 40 60° 

FIG. 8 — VERTICAL DISTRIBUTION TEMPERATURE IN CENTRAL PART OF PACIFIC 



i 2000 



; 4000 




Pacific Octan 
sin'O 

i 

°S 60° 40° 20° 0° 20° 40° 60° 

FIG. = 9 — VERTICAL DISTRIBUTION SALINITY IN CENTRAL PART OF PACIFIC 



>20' 



■ 2000 



:4000 



6000 




20° 0° 20° 40° 

FIG. 10 — VERTICAL DISTRIBUTION TEMPERATURE IN WESTERN PART OF PACIFIC 
(ACCORDING TO WUST) 

<340 >35.5 < 34 4 >35.0 <340 



^2000i 



!4000H 



6000 




6000 



-VERTICAL DISTRIBUTION SALINITY IN WESTERN PART OF PACIFIC 
(ACCORDING TO WUSTJ 



123 




FIG. 12— COMPARISON TEMPERATURE OBSERVATIONS, CHALLENGER , 1875, AND CARNEGIE . 1929 



124 











• 


























\ ° 








STATIONS 54-56 49-53, 57-67 

DEPTH 

meters 
100- 500 o • 
500-1500 o • 
> 1 500 a * 


















• 




O 

cd 










• 










, Q 










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\ 




















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cr o 
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(degrees centigrade) 


























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^^^^ • 


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k 


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REGION C 


(Stations 


68-75) 


■ > 


• 
• 


t 


• 
• 








1500nj 


■ ^~^^^ 


■ 


■ 


■ • 
■ 

■ 


• 


• 


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■ ^ r, » 


















500 


m 
























• 














34 4 






















356 


























UJ 

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Q_ 


























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*£ 
















• 


• 


• 
• — - 


• 


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• B" — — ____^ 
)00m 


■ 
" — -— — ■ 
■ 


s r^ 


• 

1 m^* — ' ■ 


5 


• 
00 m 






• 


i 


• 


-34.2 























FIG. 14— COMPOSITE TEMPERATURE-SALINITY RELATION, REGIONS 



126 



1 

12 . 

• 




4 


1 


5 


1 


1 

i 


2 





2 


2 


• 


















* / 




















• / 




















S\ 




















>• • 
































REC 


ION 4 (Stat 


ons 46- Al 


, 76-82) 


•s 
















. 


y/t 


















• 


























































DEPTH SYMBOL 

meters 
100- 500 • 
500-1500 ■ 
> 1500 » 





























3-4, PACIFIC OCEAN, FROM CARNEGIE RESULTS, 1928-1929 



127 







i 


L 






( 






! 




1 


3 




I 


2 
































































°0 °n 
















REGION 6 


(Stations 3! 


j-45, 46- 


18) 







o 

o 


0° 



° 


^ 


^s^_ 


1 












500 m 

a 
o ■ 





J&~^ 


• 


o 
*3o 














5V 


A D — 4 

I500m^ 


■ 


■ 


n D 


n °o . 


o a2_2- 



















• 




c 

■ 


OF 



D 


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2 
a: 

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• 


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o 


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^; > 




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-~ cr ^ o 

o 


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o 




















G 


5 


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FIG. 15 -COMPOSITE TEMPERATURE-SALINITY RELATION, REGIONS 



128 



° 


1 

4 

TEMPE 
(DEGREES C 


1 

MATURE 
ENTIGRADE) 


6 


i 


3 


2 





2 


I 


2 


4 


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1 























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o 

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2r 














REGION £ 


) (Stations t 


3-97, 159- 


62) . 


os^ 

• 


















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Q*^° 


^ 


• 


















■ • 

I 

o 


j>^ 
















SYMBOLS 























STATIONS 35 

DEPTH 

meters 
100- 500 
500-1500 


-45,83-94, ' 
161-162 


El 


16-48, 95-97, 
159-160 

• 
■ 






• 














>I500 


A 


A 





























5-6, PACIFIC OCEAN, FROM CARNEGIE RESULTS, 1928-1929 



129 




FIG. 16 -COMPOSITE TEMPERATURE-SALINITY RELATION, REGIONS 



130 



1 


4 




r 
5 


i 


3 


2 


3 


2 


2 


2 


4 


















• 




• 


• 


















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• 
• 




• 




• 
















• 




• 














• 


• 






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) ^f^ 








• / 




















/• 


• 




















/ • 


/ • 




















• 


• 
• • 


















• 




• 














DEPTH 

meters 

100- 50 

500-150 

> 1500 


SYMBOL 

• 
■ 






1 














> 

































7-9, PACIFIC OCEAN, FROM CARNEGIE RESULTS, 1929 



131 



ao 




































\ • 








o 

| • ■ 41 
















•\ 








DEPTH 
meters 

100- 50 
500-150 

=-1500 






• \ 


























• 








' 


*\» 














\ • 




^_» 






\ • 














\ • 


• 








• \ 


• 
\ • 












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• 










rs 




' 


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• \ 










E \ 
o \ 


• 






• \ 


< 

6§ 














<=f 




\" 






TEMPE 
(DEGREES C 




to 


• «\ • 








cry 
O 

o 

1— 


■ 


\ 










O 
1— 
■< 




\ ' 






h- 

o 




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O 




) 


m ^ 






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in 








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1 


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■ 


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■ / 










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o 7 

— s + 

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D 
t 




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c 


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1 
r 








3 





o 



132 





i-A 

>v 1 ■ 

* NJ 

* * l\. 

1500 m\ 


r 
3 

■ 
■ 




1 
5 TEMPERATURE 
(DEGREES CENTIGRADE) 


1 




A 


1 1500m 

am 
N. ■ 


3 

REGI 
(Station 


3N 14 
s 118-125) 






■ \ 


1 


1 










\ 1 

■\ 

m* 


■ 








■ \ 




REGION 1 


I (Stations 


126-130) 






\ 500m 








■ 
■ 

■ 


50 


0rr# \ 

■ 


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— • 


• 


1 








• 


\ 










M* 

• 

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V 

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1 


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3 
















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h- 
Z 
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< A 

00 aTRa 












t 




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i 
150 


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1 

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V^ 














• X^ 














REGION i; 


3 (Stations 


115-117) 
















■ \ 

5 


1 

3o\ 
























\ • 




• ^^ 








DEPTH 

meters 

100- 50 

500 - 150 

>I500 


SYMBOL 

• 
■ 

A 










^> 




• 















FIG. 1 8 -COMPOSITE TEMPERATURE-SALINITY RELATION, REGIONS 12-14, PACIFIC OCEAN, FROM CARNEGIE RESULTS, 1929 



133 




o 
o 



134 





b 


20 TEMPERATURE 2.4 


2,8 


3,2 










(DEGREES CENTIGRADE) 




















■ | 


. Q 1 • 


• 


35-39 
















A 


a i 




















2500'm 2000m 




• 




34.6 






















• 

15 


OOrn 








■ 






















■ 



D In 


2000m 






42-57 


















D 






















■ 








• 




• 














■ 


D 






• 


i • 
















: 




□ 


> 










o 












a 2500 m 




• 
















CD 








, 34.0 








D 


• 




• 


° 


• 
























1500 m 


o 








1 


1 


1 




1 










A 






D 












i 










i 


















A 




— « — i — 

A 
A 




i r — 




2000 m 


• 58-67 


















' — "—--J: 





















3000 rr 


2500 m Q 




1 D 




— ,^«^ 






























6 














J4 














"• ' — -^ 










| 










h 






• 


o 
<J — 




O 


r- 






3000 m 










1500 m 






r ■* 






A 














o 




rn 






A 


D 
















- 






A A 
AM 




— ■ — -raj] 

O] 


D 1 


• 


58-82, 






o 




Z" 






1 " □ 


□ D j 


» "■ ■»— «_^_ 


• 










_ UJ 






2500 m 




• 








o 




^)<Zj 








2000 m 






• 










3£l 

OQC 










• 


• 




• 







a 346 




UJ 

UJ CL 

I 










• 






1500 m 


o 




o 


< 






















CO 
















i 










3000 m 




















A A 


AAA 


2500 m 


D 


83-100, 


159-162 














7l ■ 


■ 




















A 




■ 


ao cd a 




















I r 




_OD 






• 


















i ■ 




a 




• » •• 
















A 1 

■ 




D 

a 






• 




1500 m 










" 





• 


• 




34-6 


o 















2000 m 


• 
• • • 




— -^_^__^ < 





5 < 


■ 













• • 

1 







( 




3 " — — 


3 




3C 


00 m 2500 


m 










1 








A 
A At A 

Mi"* * 


A 
A ■■ 

■ ■ ■ 




D 




101-109, 131-158 












i 





















A MA 


■ ■ *w~- 




t— ^JDD 







• • 












A A 


■ ■ 


DO 


a^ — S^D I 


• • 


• 








? 






■ 1 




2 


a a ar* — < 




• • 














■ ' 


3 ■ 


D V~ 


m m 


- 34. 6 


1500 m 

















• 






o 


















2C 


00m # 

• • 


• • 


• • 


• 


__•_ 


O 







O 
















• 
















• 







O 

o o 




• 




o 








I , 




















A 


■ j 


D 


110-130 
















A 


I D ' 






• 
















3000 rr ■ 


tj*"^ 


• 1 


• • 










DEPTH SYMBOL 






2500 m 


k^< 












meters 














• 








1400-1500 o 








2000m 


•^"""--s^^ 






; 




1500-2000 • 










• "-- 


^*^ 








2000-2500 a 

























2500-3000 ■ 
>3000 1 » 




• »o* 






34.0 














• 






















1500 rr 


































FIG.20A-COMPOSITE TEMPERATURE-SALINITY RELATION, PACIFIC OCEAN, FROM CARNEGIE RESULTS, 1928- 1929 



135 




136 




or 
< 



or 

UJ 

s 

Li- 

o 

CO 

UJ 

ex: 



or 



o 
i— 
I— 

o 



137 




FIG. 22-CURRENT-CHART, PACIFIC OCEAN, FROM OBSERVATIONS OF SALINITY AND TEMPERATURE 
OF SEA WATER BY THE CARNEGIE, 1928-1929 




FIG. 23 — PACIFIC CURRENTS IN NORTHERN SUMMER FROM PRELIMINARY SKETCH BY A. MERTZ 



LONGITUDINAL CROSS-SECTION; 



NORTHERLY POLAR FRONT; 



-A__ 



SOUTHERNLY POLAR FRONT: 



SUBTROPICAL CONVERGENCE; 



LIMITS OF EQUATORIAL COUNTER-CURRENT 



138 




HATCHED AREA HEAVY WATER 

LIGHT CURVED LINES PROFILES ISOBARIC SURFACES 

WEST, EAST DIRECTION TOWARD WHICH CURRENT RUNS 




FIG. 24-SCHEMATIC REPRESENTATION POSSIBLE FIELDS DENSITY AND PRESSURE, VINCINITY OF EQUATOR, 

FROM CARNEGIE RESULTS, 1928-1929 




HORIZONTAL SCALE 



400 800KM 



EIG. 25 -PROFILE 'ISOBARIC SURFACES FROM CARNEGIE RESULTS, 1929 



139 



1 59 1 58 




HORIZONTAL SCALE 



400 800KM 



FIG. 26— VERTICAL DISTRIBUTION DENSITY, NORTH-SOUTH SECTION CROSSING EQUATOR, 
FROM CARNEGIE RESULTS, 1929 

149 



159 158 




400 800 KM 



HORIZONTAL SCALE V , 

FIG. 27-VERTICAL DISTRIBUTION SALINITY, NORTH-SOUTH SECTION CROSSING EQUATOR, 

FROM CARNEGIE RESULTS 1929 

; 



140 



I 59 I 58 



56 155 154 153 152 151 




HORIZONTAL SCALE 



400 800KM 



FIG. 28-VERTICAL DISTRIBUTION TEMPERATURE,. NORTH-SOUTH SECTION CROSSING EQUATOR, 

FROM CARNEGIE RESULTS, 1929 



I 59 I 58 




HORIZONTAL SCALE 



400 800HM 



FIG. 29-VERTICAL DISTRIBUTION OXYGEN, NORTH-SOUTH SECTION CROSSING EQUATOR, 

FROM CARNEGIE RESULTS 1929 



141 



102 103 104 




HORIZONTAL SCALE 

FIG. 30-PROFILE ISOBARIC SURFACES, FROM CARNEGIE RESULTS, 1929 

95 96 97 98 99 100 101 !02 103 104 




HORIZONTAL SCALE L 



FIG. 3 1 -VERTICAL DISTRIBUTION DENSITY, NORTH -SOUTH SECTION CROSSING EQUATOR, 
FROM CARNEGIE RESULTS, 1929 



142 



101 102 103 104 




HORIZONTAL SCALE U 



FIG.32-VERTICAL DISTRIBUTION SALINITY NORTH-SOUTH SECTION CROSSING EQUATOR, 
FROM CARNEGIE RESULTS, 1929 

95 96 97 98 99 100 101 102 103 104 




OOKM 



FIG. 33— VERTICAL DISTRIBUTION TEMPERATURE, NORTH-SOUTH SECTION CROSSING 
EQUATOR, FROM CARNEGIE RESULTS, 1929 



143 




144 




145 




146 




147 




148 



DISCUSSION OF THE CARNEGIE SOUNDINGS 



The fact that the scientific program of the Carnegie 
did not permit of running parallel lines of soundings 
close together resulted in long single lines of soundings 
with few intersections. Consequently the data collected 
cannot be used alone for the construction of a bathymet- 
ric chart, but can be used to modify existing charts 
based on other data and in the construction of profiles 
along the course of the vessel. Such profiles reveal 
some of the major features of bottom relief and the 
general depth level of the oceanic sections traversed. 

Attention may well be called to some of the features 
brought out on the profiles. On profile no. 8 is to be 
seen what has been named Merriam Ridge in about lati- 
tude 25° south and longitude 82° west. Its location with 
respect to the islands of San Felix and San Ambrosio 
makes it seem probable that a submarine ridge extends 
in a general northwest- southeast direction here, and 
that the two islands are the high points of the ridge. 

On profile no. 9 at about latitude 15° south and long- 
itude 98° west, Bauer Deep reaches a sharp depression 
of about 1500 meters below the nearby bottom. Farther 
to the west in this profile is the island of Tatakoto at 
about longitude 138° 20' west. West of Tatakoto is 
Amanu Island at about longitude 140° 45' west and west- 
ward of this we see a platform extending from about 
longitude 141° 40' west to about 142° 30' west. This is 
possibly a part of the platform on which rests the island 
of Tauere or St. Simeon, just to the north in about lati- 
tude 17° 20' south. West of this platform in about lati- 
tude 18° south and longitude 145" west two soundings 
indicate the crossing of a ridge which is probably the 
extension to the southeastward of the base of Anaa or 
Chain Island. In about longitude 148° west is Mehetia 
Island with depths of more than 3000 meters between it 
and Tahiti. Farther to the west in the approach to the 
Samoan Islands, the base of Rose Island is discernible 
and a depth of more than 3500 meters separates the is- 
lands of Tutuila and Upolu. 

In profile no. 11 the steep eastern and western ap- 
proaches to Wake Island are seen at about longitude 166° 
40' east. From Wake Island westward to Guam the Car - 
negie traversed an ocean whose bottom was previously 
known to be very irregular and characterized by the sub- 
marine mountains such as appear in this part of the pro- 
file. Toward the western end of this profile the northern 
arm of Nero Deep was crossed in about longitude 147° 
20' east with soundings of 7846 and 7448 meters. 

At about 24° north latitude in profile no. 12 we see 
Fleming Deep, in which the deepest of the Carnegie 
soundings were taken, namely, 8323 and 8347 meters. 
Soundings taken September 13 to 19, 1899, by the U.S.S. 
Nero about 30 miles west of the Carnegie positions hint 
at the existence of the deep but apparently were taken 
well up on the western slope. It seems probable that the 
Carnegie soundings also are west of the deepest part. A 
sounding of 7575 meters shown on Japanese Hydrographic 
chart no. 6080 at 23° 00' north latitude, 144° 55' east 
longitude, is probably on the southern border of this 
deep. Heavy weather (including two typhoons) produced 
so much extraneous noise in the hydrophones that it was 
impossible to take any soundings between about latitude 
31° 40' north and latitude 33° 20' north. This was much 
lamented, as during this period our course lay across 



the southern,/ and what is probably the deepest, part of 
the extensive Tuscarora Deep. Farther north in this 
profile, between about latitude 36° north and 37° north, 
this deep was again crossed. 

A newly discovered submarine mountain is shown in 
profile no. 13 at about latitude 46° 30' north and longi- 
tude 169° 30' east. It is rather broad, but rises from 
1500 to 2000 meters above the surrounding ocean floor. 

Between San Francisco and the Hawaiian Islands, 
and shown in profile no. 14 at about longitude 127° 50' 
west, is a submarine mountain which has been named 
Hayes Peak. This mountain rises precipitously from 
depths greater than 4000 meters to within 1400 meters 
of the surface. The charts show a similar mountain 
about 20 miles WSW1/2W of Hayes Peak. This would 
suggest an error in position were it not probable that 
many such submarine mountains exist in this vicinity. 

North of Honolulu, and shown in profile no. 16 at 
about latitude 25° 40' north, is a rise which has been 
named Ault Peak. Although it was far from being com- 
pletely explored, the shallowest sounding over it gave a 
depth of 2548 meters, indicating an elevation of more 
than 2000 meters above the neighboring ocean bottom. 

In profile no. 21 the northeast and southwest ap- 
proaches to Penrhyn Island are shown in about longitude 
158° west. Similar approaches to Manahiki Island are 
shown in about longitude 161° west with the trough be- 
tween the two islands reaching a depth of 5899 meters. 
Manahiki Island stands as a sharp peak on a broad plat- 
form the depth of which is between 2500 and 3000 meters; 
depths of more than 5000 meters separate it from the 
Samoan Islands. 

Let us now consider how the soundings of the Car - 
negie require changes in our previous conceptions of 
the most probable course of the depth contours in the 
ocean areas traversed. Some base map must be selected 
for reference and, although it is not up to date in many 
respects, the Monaco "Carte Generale Bathym§trique 
des Oceans" has been chosen as being most complete 
and most generally available to hydrographers. Refer- 
ence is hereafter made to this chart with two exceptions, 
namely, the area between southern Greenland and New- 
foundland, where the reader is referred to part 1 of the 
Scientific Results of "The Marion expedition to Davis 
Strait and Baffin Bay," Bulletin No 19, U. S. Treasury 
Department, Coast Guard, Washington, 1932, and in the 
region of the seas adjacent to Japan, where reference is 
made to the Japanese Hydrographic Department chart no. 
6080. 

On the Norwegian Sea slope and on the Iceland side 
of the saddle in the Faroe-Iceland Ridge, soundings 64 
and 65 indicate that the 500-meter contour line should be 
moved somewhat to the northeast. On the southeastern 
coast of Iceland, between longitudes 15° and 17° west, 
the 1000-meter contour needs to be moved southward to 
include soundings 75 and 76. The tongue of the 1000- 
meter contour off Cape Reykjanes, Iceland, requires an 
S-shape on its western side to pass between sounding 99 
and the group 100, 101, and 102. The adjacent 2000- 
meter contour southwest of here needs to be bent some- 
what to the east to pass between soundings 107 and 108. 
Following this same contour toward the south, another 
S-pattern is embroidered on it, centered at about 58° 



149 



150 



OBSERVATIONS AND RESULTS IN PHYSICAL OCEANOGRAPHY 



north latitude and 34° west longitude, by soundings 122, 
123, 124, and 125. The adjacent 3000-meter line west of 
this is embayed toward the east to soundings 113 and 
114, and passes between soundings 129 and 130. As the 
Carnegie soundings between southern Greenland and the 
Grand Banks were considered in the preparation of the 
bathymetric chart in "The Marion expedition to Davis 
Strait and Baffin Bay," Scientific Results, part 1, refer- 
ence is made to that chart for this area. 

Again referring to the Monaco chart, two soundings 
(nos. 21 and 23) of between 3000 and 4000 meters are lo- 
cated within the 4000-meter contour of the East Atlantic 
Depression. Whether these are isolated peaks or con- 
nect with the 3000- to 4000-meter bottom to the west and 
northwest is open to question. The northern part of the 
Azores Plateau apparently is more extensive than indi- 
cated on the chart, the 3000-meter contour on the east- 
ern side extending to the northeastward to include sound- 
ings 19 and 20, and on the western side extending to the 
westward to include soundings 13 to 17 inclusive. Sound- 
ing 18 represents a new peak of the group near Chaucer 
Bank. Soundings 11 and 12, together with the now al- 
tered shape of the 3000-meter contour, make it seem 
probable that the 3000- to 4000-meter area between 
latitudes 42° and 44° north and between longitudes 37° 
and 38° west is connected with the continuous 3000- to 
4000-meter belt along the western side of the Middle 
Atlantic Rise. 

East of the southern tip of the Grand Banks the 
4000-meter contour needs to be pushed somewhat to the 
eastward to include soundings 163, 164, and 165, and 
somewhat south of this, in about latitude 41° 30' north, 
needs an indentation to exclude sounding 169. Still 
farther south between about latitudes 37° 30' and 38° 30' 
north, the 5000-meter line should be extended westward 
to conform to soundings 175, 7, 176, and 177. Then it 
is embayed eastward in the vicinity of the 37th parallel 
in consideration of soundings 178 to 183 inclusive. 
Soundings 184 to 189 inclusive indicate that this 4000- 
to 5000-meter arm is connected by means of a low ridge 
to the general 4000- to 5000-meter belt along the west- 
ern side of the Middle Atlantic Rise. This leaves an 
isolated depression of more than 5000 meters depth run- 
ning northeastward from the ridge just mentioned. As 
one approaches the Dolphin Plateau from the northwest, 
the 4000-meter line should be moved somewhat west- 
ward to pass between soundings 190 and 191; the 3000- 
meter contour either cuts the plateau into two sections 
or is deeply embayed on each side to conform to sound- 
ings 197 and 198. 

On the eastern slope of the Middle Atlantic Rise in 
this vicinity, the 4000-meter line is extended sharply 
southward by soundings 201 to 204 inclusive. Sounding 
206 moves the 5000-meter contour eastward. Sounding 
208 may either represent an isolated pool or a narrow 
valley communicating with Moseley Deep. The embay- 
ment demanded just south of here by soundings 211 and 
213 lend favor to the valley idea. Farther south in 
about latitudes 15° to 16° north, soundings 220, 221, and 
225 may again require the considerable invasion of the 
Moseley Deep by the 5000-meter contour or they may 
be isolated elevations. Still farther south in about lati- 
tudes 10° to 12° north, this same 5000-meter line takes 
on a very complicated pattern with a general displace- 
ment to the southwestward by soundings 231 to 234 in- 
clusive and 243 to 249 inclusive. Because of lack of 
data it is difficult to state on which side of the Middle 



Atlantic Rise sounding 238 is located, but in either case 
one of the 4000-meter lines must be altered to accomo- 
date it. 

Between about latitudes 11° and 12° north the 4000- 
meter line on the eastern side of the Middle Atlantic 
Rise takes on an S-pattern to conform to soundings 253 
to 257 inclusive. Crossing the rise at this latitude a 
3000-meter contour is required to encircle soundings 
261 and 262. The 4000-meter line is extended in a spur 
to the westward; the isolated area deeper than 5000 me- 
ters just to the south of this spur is greatly diminished. 

Near here, the southeastern corner of the 5000- 
meter contour of the West Atlantic Depression is em- 
bayed to the eastward so as to pass between soundings 
270 and 271, the northern boundary of the embayment 
following more or less the line of soundings 271 to 282 
inclusive. Just east of Barbados the 3000-meter contour 
line should be moved northward to include soundings 300 
to 302 inclusive. 

In the Caribbean Sea south of Porto Rico, sounding 
315 apparently indicates an isolated peak which must be 
encircled by a 4000-meter contour. Farther to the west 
between Haiti and western Venezuela and about midway 
between them, soundings 318 and 319 indicate the pres- 
ence of a rise which must be encircled by a 4000-meter 
contour. 

In the southeastern Pacific one of the most impor- 
tant revelations of the Carnegie soundings is that the 
threshold level of the Easter Island Rise is of a depth 
less than 3000 meters from about latitudes 9° to 39° 
south. The 3000-meter contour on the western side of 
the rise extends in a general northerly direction from 
about latitude 39° south and longitude 113° west to about 
latitude 15° south and longitude 115° west, and thence 
northeastward to about latitude 9° south and longitude 
108° west. From this point it curves southward, along 
the eastern side of the rise, concave toward the east, 
passing close to the northern side of Easter Island, then 
extending to the east to include the rocks of Sala y Gomez, 
then following an irregular course to about latitude 36° 
south and longitude 104° 30' west, and then southwest- 
ward to close the area. These surmises are based on 
soundings 373 to 421 inclusive and 543 to 547 inclusive 
combined with the chart values. 

Soundings 424 to 429 inclusive indicate that the em- 
bayed 4000-meter line to the south of the Easter Island 
Rise at about longitude 100° west does not come as far 
north as has been supposed. Merriam Ridge, disclosed 
by soundings 458 to 461 inclusive, seems probably to be 
an extension to the northwest of the base on which rest 
the islands of San Felix and San Ambrosio. Just north 
of Merriam Ridge, soundings 463 and 464 require that 
the 4000-meter contour be moved somewhat to the south; 
soundings 468 to 471 seem to show that the isolated area 
of between 3000 and 4000 meters depth is larger than 
that shown on the chart as a narrow strip between about 
latitude 17° south and longtiude 75° 30' west and about 
latitude 15° south and longitude 77° west. 

Soundings 481 and 482 show that the 5000-meter con- 
tour of the Milne-Edwards Trench extends farther to the 
northwest. The 4000-meter line on the eastern side of 
the Easter Island Rise apparently follows the course of 
the Carnegie from about longitude 92° west to about 
longitude 105° west, weaving in and out among soundings 
505 to 534 inclusive, with Bauer Deep at sounding 519 as 
a narrow deep bay. 

The caldron in the Easter Island Rise, shown on the 



DISCUSSION OF CARNEGIE SOUNDINGS 



151 



chart between about latitudes 3° and 9° south and about 
longitudes 100° and 104° west, is modified by soundings 
366 to 369 inclusive. 

Malpelo Island is shown on the chart as resting on a 
platform of less than 3000 meter depth, which is con- 
nected to the South American continent. Soundings 340, 
and 343 to 346 inclusive, however, indicate that this 
platform is separated from the continent by a channel 
greater than 3000 meters in depth and having a small but 
deep depression in its middle (sounding 344). 

On the western side of the Easter Island Rise sound- 
ings 577 to 601 inclusive require that the 4000-meter 
contour line extend in a long tongue as far west as long- 
itude 131° west in about latitude 17° south. 

In the Tuamotu Archipelago soundings 620 to 662 in- 
dicate that the 4000-meter line surrounding the northern 
group includes the islands of Angatau, Fakaina, Rekare- 
ka, Taueri, Tatakoto, Pukaruha, and Reao, were it not 
for the single old sounding of 4000 meters at latitud. 
18° 08' south, longitude 141° 49' west. Soundings 668 
and 669 show that the base of Anaa Island extends to the 
southeastward. In the Society Islands soundings 687 and 
688 of more than 3000 meters separate Morea from 
Husheine; soundings 699 and 700 may mean that a chan- 
nel deeper than 4000 meters separates Bellingshausen, 
Scilly, and Mopelia from the rest of the group. West of 
of Tahiti and south of Raiatea the 4000-meter line needs 
to be moved south to conform to soundings 694 and 695. 

West of the Society Islands in about latitude 16° 
south the 5000-meter contour is more deeply embayed 
to the east, as is shown by soundings 712 to 723 inclu- 
sive. Following westward along the north side of this 
bay, this contour continues until about the position of 
sounding 731 and thence northward nearly to Nassau Is- 
land to pass between soundings 1482 and 1483. North- 
eastward of Danger, Nassau, and Suwarrow islands lies 
the large submarine platform on which stand the islands 
of Manahiki and Ryerson. A 4000-meter contour line 
apparently surrounds this entire area, and a sizable 
area within this is enclosed in a 3000-meter line (sound- 
ings 1458 to 1480 inclusive). Soundings 1452 to 1455 in- 
clusive show a trench of more than 5000 meters between 
Manahiki and Penrhyn islands. 

East of Starbuck Island soundings 1423 to 1426 show 
the 5000 -meter line to be embayed somewhat to the north; 
depths between Maiden Island and FilippoBank are great- 
er than 4000 meters. At sounding 1415 the bottom is ele- 
vated about 800 meters above the neighboring floor. 

Between about longitudes 149° and 160° west, the 
chart shows a 5000-meter contour running in an east- 
west direction just north of the equator. The chart also 
shows a 5000-meter line surrounding Christmas, Fan- 
ning, Washington, and Palmyra islands. The paucity of 
soundings southeast of Fanning Island leaves much to 
conjecture, yet in view of soundings 1389 to 1410 inclu- 
sive it seems likely that this area is all of depth less 
than 5000 meters and that the 5000-meter line runs from 
a point just west of Jarvis Island northward to meet the 
chart line at about latitude 2° north, longitude 160° west, 
that it then follows the course on the chart around the 
islands mentioned as far as about latitude 7° north, 
longitude 156° 30' west, whence it follows the 7th paral- 
el eastward to again join the chart line northward near 
longitude 149° west. This must remain a conjecture 
until more data are at hand. Soundings 1403 to 1408 in- 
clusive indicate that a small closed 4000-meter contour 
is required in this vicinity. 



A 5000-meter contour line apparently follows the 
course of the Carnegie from soundings 1332 to 1396, 
threading in and out among the soundings. This would 
indicate two things, namely, that an extensive arm 
thrusts southwestward from what is shown as a caldron 
centered about 11° north latitude and 130° west longi- 
tude, and that the supposed caldron is in communication 
with and is not shut off from the 5000- to 6000-meter 
depths of the North Pacific Basin. 

Between about longitudes 138° and 144° west an 
east-west 5000-meter contour is shown between lati- 
tudes 24" and 25° north. This needs to be moved farther 
south to conform to soundings 1314 to 1319 inclusive and 
1190 to 1193 inclusive. This same 5000-meter contour 
farther north, in about latitude 30 Q 30' north and longi- 
tude 140° west, must be extended northward in view of 
soundings 1289 to 1292 inclusive. 

A sounding (no. 1282) of less than 5000 meters ap- 
pears at longitude 145° west and a sounding of more 
than 6000 meters (no. 1250) appears northwest of Mur- 
ray Deep. The 5000-meter line north of the Hawaiian 
Islands probably extends northwestward as far as about 
latitude 28° 30' north and about longitude 161° west 
(soundings 1229 to 1238 inclusive). From this base Ault 
Peak (sounding 1231) rises to a depth of 2548 meters. 

The Hawaiian, Gilbert, and Marshall groups are all 
shown as having a common base of less than 5000 meters 
depth. The southern part of this 5000-meter contour line 
is shown on the chart as being just south of the equator 
and just north of the Phoenix group. Soundings 798 to 
824 inclusive seem to indicate that the 5000-meter line 
is deeply embayed northwestward with a deeper area 
between the Gilbert and Marshall groups to the south- 
west and the Hawaiian group to the northeast. The 
southern part of the 5000-meter line around the Hawai- 
ian group is apparently moved northward to about lati- 
tude 3° north to pass between soundings 807 and 808, 
thence northwestward and returning north between sound- 
ings 815 and 816. The line probably continues to the 
north to connect with what is shown on the chart as a 
closed depression of more than 5000 meters in the 
neighborhood of latitude 20° north, longitude 175° west. 
From the western end of this supposed depression, the 
5000-meter line probably continues southwestward, join- 
ing the chart line at about latitude 19° north, longitude 
178° east. Soundings 839 and 841 seem to show that a 
low ridge connects this western end of the Hawaiian Rise 
with the Marshall base near Taongui Island- -the north - 
ermost of the Marshall group. A small area enclosed 
by a 6000-meter contour is required by soundings 823 
and 824; a 4000-meter line must surround sounding 814. 
Soundings 830 to 833 indicate another small uncharted 
rise. 

We find from soundings 849 to 859 inclusive that the 
5000-meter line surrounding Wake Island extends much 
farther to the southeast of the island than to the north- 
west. 

Referring now to Japanese Hydrographic Department 
ChartNo. 6080, Carnegie soundings 865 to 873 inclusive 
introduce new contour patterns around the submarine 
mountains at about latitudes 20° to 22° north and longi- 
tudes 162° to 162° east. Additional newly found peaks in 
this submarine range between this locality and Nero 
Deep are shown by soundings 883, 896, and 900. On the 
western border of Nero Deep east of Rota Island, sound- 
ings 906 and 907 require the 5000- and 6000-meter lines 
to be moved more to the eastward. 



152 



OBSERVATIONS AND RESULTS IN PHYSICAL OCEANOGRAPHY 



Soundings 934 and 935 require the introduction in 
Fleming Deep of an 8000-meter contour, and the extension 
of the 6000- and 7000-meter lines in this vicinity. South 
of Fleming Deep sounding 930 shows an isolated peak, 
and to the north of Fleming Deep another isolated peak 
is evidenced by sounding 944. 

Near the southern end of Tuscarora Deep the east- 
ern 6000-meter line must be moved somewhat more to 
the east to conform to soundings 948 and 949, whereas 
farther north sounding 959, on the western slope of the 
deep, requires the 7000-meter line to be moved to the 
eastward. East of Tokio soundings 965 and 966 show 
that the 2000-meter contour and probably the 3000- 
meter line need to be moved eastward. 

Somewhat farther north and on the eastern slope of 
Tuscarora Deep, soundings 972 to 977 inclusive intro- 
duce an S-shaped irregularity into both the 6000- and 
7000-meter lines and diminish the area enclosed in the 
8000-meter contour. 

Soundings 1021 to 1048 inclusive, of which nos. 1022, 
1026, 1027, 1032, 1033, 1043, and 1047 are greater than 
6000 meters, suggest that a 6000-meter contour runs 
along the 47th parallel from about longitudes 165° to 175° 
east, and that this represents the southern boundary of 
a connection between the Kamchatka Trench and the 
Aleutian Deep. Soundings taken by the U. S. S. Ramapo 
have been published by the U. S. Hydrographic Office in 
a "List of oceanic depths 1931, North Pacific Ocean," 
H. O. no. 210a, Washington, 1932. Soundings listed in 
this publication as "route no. 8," on pages 4 to 12 in- 
clusive, parallel the route of the Carnegie somewhat to 
the southward between Japan and San Francisco. As pub- 
lished, they are based on a constant sounding velocity of 
1463 meters per second. Those soundings between lati- 
tude 34° 01' north, longitude 140° 41' east, and San Fran- 
cisco have been corrected for sounding velocity accord- 
ing to the Carnegie data. Comparing these soundings 
with the Carnegie soundings, there seems to be a low 
rise on the seaward side of Tuscarora Deep, Kamchatka 
Trench, and Aleutian Deep, separating these from the 
deep basin of the North Pacific. A submarine mountain on 
this rise is disclosed by soundings 1029, 1030, and 1031, 
with another such mountain indicated by sounding 1038. 

Referring once more to the Monaco chart, it would 
seem from soundings 1050 to 1062 inclusive, of which 
nos. 1050, 1061, and 1062 are less than 5000 meters, that 
the 5000 -meter contour borders the southern part of the 
Aleutian Deep as far westward as about longitude 177° 
west before it turns southeastward. 



One other notable departure from conditions indicat- 
ed on the charts has yet to be considered. This is a wire 
sounding of 1344 ± 40 meters at oceanographic station 40 
in latitude 1° 32' south and longitude 82° 16' west. This 
was named Carnegie Ridge, but in the absence of other 
soundings we can only remark that it occurs in an area 
where the chart shows a depth of between 3000 and 4000 
meters. 

The names "Carnegie Ridge," "Merriam Ridge," 
"Bauer Deep," "Fleming Deep," and "Hayes Peak," 
assigned by Captain J. P. Ault to these various features 
at the time of their discovery, have been retained in this 
discussion along with the name "Ault Peak," which was 
christened after Captain Ault's death. 

Some of the profiles of approach to land in the Pacific 
are shown in the accompanying diagram (fig. 1). These 
are all islands and are, therefore, shown along with the 
maximum slope which is theoretically stable according 
to Littlehales (Bull. Nat. Res. Council, no. 17, pp. 90-93, 
1922). Inasmuch as some of these islands have an ap- 
preciable mass above the water level, a strict compari- 
son is not justifiable. In order to better compare the 
actual bottom slopes, all the curves have been started 
from the shore line and the distance of the center of the 
peak from the shore line has been given in tabular form 
to enable the reader to differentiate between the large 
and small islands. Of the nine islands, the approaches 
for which are shown, four are grouped as large and five 
as small. An interesting feature which offers food for 
thought is that four of the five small islands shown have 
a secondary ridge or elevated prominence on their north- 
eastern sides, whereas the fifth (Wake Island) was not 
approached from this direction. In the case of Penrhyn 
Island, this ridge apparently comes very close to the 
surface and is known as Flying Venus Reef. The data 
are, of course, too meager for conclusions, and the ab- 
sence of similar ridges on the other sides of these is- 
lands, as indicated by the Carnegie soundings, may be 
owing to too great an interval between soundings, rather 
than to the actual nonexistence of such irregularities. 
In the case of Amanu Island, the apparent irregularity 
may not be real and may only be the result of the devious 
path of approach. 

These findings, as well as the entire sounding pro- 
gram of the Carnegie , stress the need of more thorough 
exploration of the ocean depths and impress one with the 
inadequacy of our present knowledge of the bottom fea- 
tures. 




FIG. I— SLOPES OF ISLANDS AS DEVELOPED FROM SONIC-DEPTH RESULTS ON CRUISE VII OF THE CARNEGIE 

OCEAN, OCTOBER, 1928, TO NOVEMBER, 1929 



PACIFIC 



153 



INDEX 



Aleutian Deep, 152 

Antarctic circumpolar current, 105 

oxygen content, 105 
Antarctic intermediate current, 112 

North Atlantic, 84,85,86 
Antarctic intermediate water, South 
Pacific, 94, 95 

origin, 102 

oxygen content, 102 

salinity and temperature, 94, 95 
Arctic intermediate current, 112 
Arctic intermediate water 

origin, 102 

oxygen content, 102 

temperature and salinity, 97, 98, 99 1 
Armauer Hansen . 86 
Atlantic Drift, 87 
Ault Peak, 149,151,152 
Azores Plateau, 150 



Bauer Deep, 149, 150, 152 
Bottom samples 
collection, 79 

snapper -type sampler, 79 

illustrated, 80 
tube sampler, 79 
illustrated, 80 
preservation, 79 
Bottom temperature (see Temperature) 
British Admiralty tables, 51, 61 
Bushnell . 77 



California Current, 109 

velocity, 113 
Carnegie Ridge, 152 
Challenger . 85, 86, 88, 89 
Chaucer Bank, 150 
Conductivity method of measuring sa- 
linity, 67 
Convection layer 

changes in thicknesr across the 
equator, 96 

increase in thickness toward the 
west, Pacific, 95 
Currents (see also geological names) 

computation, 106 

relation to prevailing winds, 107 



Dana . 77, 84, 85, 86 
Deep water 

of Pacific, 93 
origin, North Atlantic, 84 
Pacific Basin, 89 
origin, 104 
oxygen content, 104 
table, 104 
Pacific, temperature and salinity, 
102 

table, 103 
Peruvian Basin, temperature, y4 
Peruvian Sea, 85 
potential North Atlantic, tempera- 
ture, 86 
potential Pacific, 104 

table, 104 
salinity 

Pacific 77 
North Atlantic, 77, 85 
temperature, 85 
sounding velocity, observations, 61 
Deep-water circulation 
Atlantic, 105 
Pacific, 106, 113 
Density distribution 
Pacific, 100 
maintained by prevailing winds, 107 



Depth 

by thermometers compared with 

wire length, 12 
comparison of depth by thermome- 
ter, wire, and sonic methods, 
55-58 
determined thermometrically, 11, 12 

accuracy, 14 
of sampling, 15 
accuracy, 16 
ratio between depth and wire length, 

15 
ratio between depth to bottom and 

wire length, 47 
ratio of true depth to intermediate 
sonic, 58 
Depth finding equipment, sonic, 51 
Discovery n, 104, 105 
Dolphin Plateau, 150 



East Atlantic Depression, 150 
Easter Island Rise, 150, 151 
Equatorial Countercurrent, 109, 110, 
111 
oxygen content, 111, 112 
velocity, 113 
Equatorial currents (see North and 

South Pacific tropical currents) 
Evaporation, importance to surface 
temperature and salinity, 94 



Fleming Deep, 149, 152 
Flying Venus Reef, 152 



Grand Banks of Newfoundland, 
Gulf of Alaska, current, 109 

velocity, 113 
Gulf Stream, 61,87 



84,150 



Hayes Peak, 149, 152 
Humboldt Current (see Peruvian Cur- 
rent) 



Intermediate subpolar currents, Pa- 
cific, 88 
Intermediate water of Pacific, 93 
Isobaric surfaces 

profiles across Equatorial Counter - 

current, 105 
profiles in North Atlantic, 87 

illustrated, 121 
topographies in Pacific, 106 



Japan Current, 61 

Kamchatka Trench, 152 
Kurile Current, 109 

velocity, 113 
Kuroshio Current, 109 



Labrador Current, 87 

Marion . 149, 150 
Maud. 6 

Merriam Ridge, 14y, 150, 152 
Meteor . 5, 6, 12, 79, 105 
Michael Sars . 83, 84, 86 
Middle Atlantic Rise, 150 
Milne -Edwards Trench, 150 
Monaco base maps, 149, 150, 152 
Moseley Deep, 150 
Murray Deep, 151 

155 



Nero . 149 

Nero Deep, 149, 151 

North Atlantic trade-wind drift, 87 

North Pacific Basin, 151 

North Pacific easterly current, 109 

velocity, 113 
North Pacific tropical current, 108, 109 

velocity, 113 



Oxygen content 

Antarctic circumpolar current, 105 
Antarctic intermediate water, 102 
Arctic intermediate water, 102 
Equatorial Countercurrent, 111, 112 
Pacific Basin, 104 
table, 104 

Oyashio Current (see Kurile Current) 



Pacific Basin (see Deep water) 
Peruvian Basin, temperature of deep 

water, 94 
Peruvian Current, 108 

velocity, 112 
Peruvian Sea, deep water, 85 
Phosphate content near Galapagos 

Island, 108 
Planet . 88, 89, 98 



Ramapo, 152 



Salinity 

accuracy of values, 77 

Antarctic intermediate water, South 

Pacific, 94, 95 
Arctic intermediate water, 97,98,99 
Atlantic deep water, 77 
effect of temperature, 72, 73 
evaporation, importance to surface, 

94 
importance of upwelling, 94 
measurement, 67 
accuracy, 73 
conductivity method, 67 
corrections, 71 
silver nitrate method, 67 
Pacific deep water, 77 
preservation of samples for meas- 
urement, 71 
relation between slide -wire readings 
and, 67 
Salinity bridge, titration comparisons 
used in calibration, 67, 68-70 
Salinity distribution, horizontal 
Pacific, 88 

illustrated, 123 
sea surface, Pacific, yl 
subsurface levels, Pacific, 91-93 
Salinity distribution, vertical, Pacific, 

93-100 
Samplers (see Bottom samples) 
Sargasso Sea, 87 
Silver nitrate method of measuring 

salinity, 67 
Sonic depth, 51-54 (see Soundings also) 
determination, 51 
accuracy, 51, 52 
basic velocity, 52 
correction factors, 51-52 
table, 52 

British Admiralty tables, 51 
Sonic depth finding equipment, 51 
Sounding 

accuracy, 62 ,. ... 

bottom profiles determined by, 149 
by shotgun method, 54, 57 



156 



INDEX 



Sounding 

profiles of approaches to land in 

Pacific, determined by, 152 
program, 52 

results of different methods, 56, 57 
with piano wire, 47 
accuracy, 48 
Sounding velocity 

deep-water observations, 61 

table, 62-63 
effect of seasonal variation, | 61 
for depths down to 2500 meters, 61 

table 2 (Oceanogr. I-B, p. 183) 
vertical sections, 61-62 

British Admiralty tables, 61 
South Pacific easterly current, 107 

velocity, 112 
South Pacific tropical current, 108 

velocity, 112 
Stratosphere, oceanic, 89 



Temperature 

accuracy of Challenger data, 89 
annual variation at 100 meters, 

Pacific, 91 
Antarctic intermediate water, South 

Pacific, 94, 95 
Arctic intermediate water, 97,98,99 
bottom water of Pacific, 102, 103 

table, 103 
effect on salinity, 72, 73 



Temperature 

evaporation, importance to surface, 

94 
North Atlantic, 83-86 
Pacific, earlier presentations, 88 
Peruvian Basin, deep water, 94 
potential North Atlantic deep water, 

86 
potential Pacific deep water, 104 

table, 104 
sea-surface values, Pacific, 90 
surface, importance of upwelling, 94 
Temperature distribution, horizontal 
sea-surface values, Pacific, 90 
subsurface levels, Pacific, 91-93 
vertical profile, Pacific, 88 
Temperatuie distribution, vertical, 

Pacific, 93-100 
Temperature -salinity relation 
North Atlantic, 86 
Pacific, 100, 101 
Thermometers 

comparison of depth, wire and sonic 

methods with, 55-58 
protected reversing, 5 

comparisons between accuracy, 

10 
errors, 5-7 
unprotected reversing 

accuracy of depth determined 

by, 14 
depth determined by, 11 



Thermometers 

depth by thermometers compared 

with wire length, 12 
errors, 11 
Thermometer reversing frames, 3 
Thorshavn . 105 
Troposphere, oceanic, 89 

topmost layer, 93 
Tuamotu Archipelago, 151 
Tuscarora Deep. 149, 152 



Upwelling 

importance to surface temperature 

and salinity, 94 
off the coast of California, 109 
off the coast of Peru, 108 



Water bottles, 3 

Water samples 
accuracy, 16 
depth, 15 

West Atlantic Depression, 150 

Wire angle, variation with depth, 15 

Wire length 

depth by thermometers compared 

with, 12 
ratio between depth and, 15 
ratio between depth to bottom and, 47 
sounding with piano wire, 47 
accuracy, 48